Latest Articles from NeoBiota Latest 100 Articles from NeoBiota https://neobiota.pensoft.net/ Fri, 29 Mar 2024 14:10:34 +0200 Pensoft FeedCreator https://neobiota.pensoft.net/i/logo.jpg Latest Articles from NeoBiota https://neobiota.pensoft.net/ Outcomes of control and monitoring of a widespread riparian invader (Tamarix spp.): a comparison of synthesis approaches https://neobiota.pensoft.net/article/111628/ NeoBiota 91: 67-98

DOI: 10.3897/neobiota.91.111628

Authors: Alexander R. B. Goetz, Eduardo González-Sargas, Mayra C. Vidal, Patrick B. Shafroth, Annie L. Henry, Anna A. Sher

Abstract: Effective ecological restoration requires empirical assessment to determine outcomes of projects, but conclusions regarding the effects of restoration treatments on the whole ecosystem remain rare. Control of invasive shrubs and trees in the genus Tamarix and associated riparian restoration in the American Southwest has been of interest to scientists and resource managers for decades; dozens of studies have reported highly variable outcomes of Tamarix control efforts, as measured by a range of response variables, temporal and spatial scales and monitoring strategies. We conducted a literature search and review, meta-analysis and vote count (comparison of numerical outcomes lacking reported variances and/or sample sizes) on published papers that quantitatively measured a variety of responses to control of Tamarix. From 96 publications obtained through a global search on terms related to Tamarix control, we found 52 publications suitable for a meta-analysis (n = 777 comparisons) and 63 publications suitable for two vote counts (n = 1,460 comparisons total; 622 comparisons reported as statistically significant) of response to Tamarix control. We estimated responses to control by treatment type (e.g. cut-stump treatment, burning, biocontrol) and ecosystem component (e.g. vegetation, fauna, fluvial processes). Finally, we compared results of the various synthesis methods to determine whether the increasingly stringent requirements for inclusion led to biased outcomes. Vegetation metrics, especially measures of Tamarix response, were the most commonly assessed. Ecosystem components other than vegetation, such as fauna, soils and hydrogeomorphic dynamics, were under-represented. The meta-analysis showed significantly positive responses by vegetation overall to biocontrol, herbicide and cut-stump treatments. This was primarily due to reduction of Tamarix cover; impacts on replacement vegetation were highly variable. We found concordance amongst our varied synthesis approaches, indicating that increased granularity from stricter quantitative techniques does not come at the cost of a biased sample. Overall, our results indicate that common control methods are generally effective for reducing Tamarix, but the indirect effects on other aspects of the ecosystem are variable and remain understudied. Given that this is a relatively well-studied invasive plant species, our results also illustrate the limitations of not only individual studies, but also of reviews for measuring the impact of invasive species control. We call on researchers to investigate the less commonly studied responses to Tamarix control and riparian restoration including the effects on fauna, soil and hydrogeomorphic characteristics.

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Review Article Wed, 21 Feb 2024 16:01:17 +0200
Substrate complexity reduces prey consumption in functional response experiments: Implications for extrapolating to the wild https://neobiota.pensoft.net/article/111222/ NeoBiota 91: 49-66

DOI: 10.3897/neobiota.91.111222

Authors: Elizabeth M. Oishi, Kiara R. Kattler, Hannah V. Watkins, Brett R. Howard, Isabelle M. Côté

Abstract: Understanding the density-dependent impacts of an invasive predator is integral for predicting potential consequences for prey populations. Functional response experiments are used to assess the rate of prey consumption and a predator’s ability to search for and consume prey at different resource densities. However, results can be highly context-dependent, limiting their extrapolation to natural ecosystems. Here, we examined how simulated habitat complexity, through the addition of substrate in which prey can escape predation, affects the functional response of invasive European green crabs (Carcinus maenas) foraging on two different bivalve species. Green crabs feeding on varnish clams (Nuttallia obscurata) shifted from a Type II hyperbolic functional response in the absence of substrate to density-independent consumption when prey could bury. Green crabs ate few Japanese littleneck clams (Venerupis philippinarum) under all densities, such that no functional response curve of any type could be produced and their total consumption was always density independent. However, the probability of at least one Japanese littleneck clam being consumed increased significantly with initial clam density and crab claw size across all treatments. At mean crab claw size and compared to trials without substrate, the proportion of varnish clams consumed were 4.2 times smaller when substrate was present, but substrate had a negligible effect (1.2 times) on Japanese littlenecks. The proportion of varnish clams consumed increased with crab claw size and were higher across both substrate conditions than the proportion of Japanese littlenecks consumed; however, the proportion of Japanese littleneck clams consumed increased faster with claw size than that of varnish clams. Our results suggest that including environmental features and variation in prey species can influence the density-dependent foraging described by functional response experiments. Incorporating replicable features of the natural environment into functional response experiments is imperative to make more accurate predictions about the impact of invasive predators on prey populations.

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Research Article Mon, 19 Feb 2024 16:32:21 +0200
Exotic pet owners’ preferences for different ectothermic taxa are based on species traits and purchase prices in the United States https://neobiota.pensoft.net/article/109403/ NeoBiota 91: 1-27

DOI: 10.3897/neobiota.91.109403

Authors: Elizabeth F. Pienaar, Diane J. E. Sturgeon

Abstract: The exotic pet trade has resulted in substantial invasion and disease risks, owing to the release of pets into new environments. Scientists have conjectured that pet owners acquire and release species with undesirable traits because they are imperfectly informed about the traits of these animals. However, few studies have used social science methods to elicit pet owners’ preferences for exotic pets. In 2019 we administered a best-worst choice survey to 1,055 exotic pet owners in the United States (who own pet reptiles, amphibians, fish, or invertebrates) to examine how human preferences and incomplete information may contribute to the risks of the exotic pet trade. Respondents preferred colorful and patterned species. On average, respondents preferred medium-sized amphibians and reptiles, small fish, and large invertebrates, although they demonstrated heterogeneity in preferences with respect to the adult size of pets. Respondents also preferred amphibians and reptiles with medium life expectancies and fish and invertebrates with long life expectancies, although they again demonstrated heterogeneity in preferences with respect to pets’ life span. Respondents preferred docile animals, and were more likely to purchase lower-cost pets. We found some evidence that respondents’ decision to purchase exotic pets depended on whether these animals were native, rare, had unusual morphological features, and breed easily. Respondents’ decision to purchase specific taxa as exotic pets also depended on their age, education, and housing. Most respondents stated that they searched for information on pets’ diet, behavior, adult size, life span, costs of care such as equipment or veterinary costs, and whether the animal was captive bred before purchasing these animals. Excepting pets’ diets, fewer than half of respondents had been offered information on pets’ traits by sellers. On average, respondents rated the information they had been offered as average. Respondents typically obtained additional information about pets from online searches. Our results suggest that certification systems that provide critical information on exotic pets’ behaviors, adult size, longevity, fecundity, and husbandry needs should be implemented to prevent pet owners acquiring animals that they may subsequently abandon.

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Research Article Mon, 5 Feb 2024 10:51:27 +0200
Asymmetrical insect invasions between three world regions https://neobiota.pensoft.net/article/110942/ NeoBiota 90: 35-51

DOI: 10.3897/neobiota.90.110942

Authors: Rylee Isitt, Andrew M. Liebhold, Rebecca M. Turner, Andrea Battisti, Cleo Bertelsmeier, Rachael Blake, Eckehard G. Brockerhoff, Stephen B. Heard, Paal Krokene, Bjørn Økland, Helen F. Nahrung, Davide Rassati, Alain Roques, Takehiko Yamanaka, Deepa S. Pureswaran

Abstract: The geographical exchange of non-native species can be highly asymmetrical, with some world regions donating or receiving more species than others. Several hypotheses have been proposed to explain such asymmetries, including differences in propagule pressure, source species (invader) pools, environmental features in recipient regions, or biological traits of invaders. We quantified spatiotemporal patterns in the exchange of non-native insects between Europe, North America, and Australasia, and then tested possible explanations for these patterns based on regional trade (import values) and model estimates of invader pool sizes. Europe was the dominant donor of non-native insect species between the three regions, with most of this asymmetry arising prior to 1950. This could not be explained by differences in import values (1827–2014), nor were there substantial differences in the sizes of modelled invader pools. Based on additional evidence from literature, we propose that patterns of historical plant introductions may explain these asymmetries, but this possibility requires further study.

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Research Article Mon, 8 Jan 2024 14:09:58 +0200
Cortaderia selloana, an example of aggressive invaders that affect human health, yet to be included in binding international invasive catalogues https://neobiota.pensoft.net/article/110500/ NeoBiota 89: 229-237

DOI: 10.3897/neobiota.89.110500

Authors: Diego Liendo, Juan Antonio Campos, Alberto Gandarillas

Abstract: Invasive plant species can suppress local biodiversity, affect soil properties and modify the landscape. However, an additional concern of plant invasions that has been more disregarded is their impact on environmental human health. Here, we discuss the case of Cortaderia selloana (Schult. & Schult.f.) Asch. & Graebn, as an example of a worldwide invasive species with a strong environmental impact. We summarise the main facts regarding the C. selloana invasion, the recent clinical evidence of its impact on human health and the great potential expansion of the species in the context of climate change. C. selloana constitutes a clear example to boost demands from policy makers for urgent and efficient measures to control or eradicate invasive species, also in ruderal areas. This aggressive invader is still out of relevant binding international invasive species catalogues, including the European List of Invasive Alien Species of Union concern (Union list), and is still subjected to extensive trading in some European countries. Therefore, including C. selloana in the Union list becomes mandatory to impose full restrictions on keeping, importing, selling, breeding and cultivating the species.

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Discussion Paper Wed, 20 Dec 2023 17:47:30 +0200
Prioritisation of quarantine pest list for the Caribbean using a multi-criteria decision approach https://neobiota.pensoft.net/article/102673/ NeoBiota 88: 1-16

DOI: 10.3897/neobiota.88.102673

Authors: Duraisamy Saravanakumar, Ezra S. Bartholomew, Govind Seepersad, Janil Gore-Francis, Juliet Goldsmith, Naitram Ramnanan, Peta Gaye Chang, Puran Bridgemohan, Renita Sewsaran, Sardis Medrano-Cabral, St. Sanya Morrison

Abstract: Quarantine plant pests are socially, economically and environmentally important due to their impact on food security, human health, global trade and crop production costs. The increase in global trade and tourism, frequent occurrence of natural disasters and climate changes have exacerbated the rate of entry, establishment and spread of plant pests regionally and globally. It has, therefore, become exigent to develop a list of pests of quarantine importance at the regional and national levels to prioritise and allocate the limited available resources to manage the associated risks. In the present study, the Technical Committee on the Formulation and Prioritisation of a Regional Priority Pest List for the Caribbean, in collaboration with the National Plant Protection Organisation of the Caribbean countries and the United States Department of Agriculture - Animal and Plant Health Inspection Service (USDA-APHIS), developed and prioritised a quarantine pest list using a multi-criteria decision-making approach. The technical committee successfully evolved the process in 2014 and 2018 and developed a list of the top 10 pests of quarantine importance for the Caribbean Region, employing the Delphi Technique (DT) and Analytical Hierarchy Process (AHP) through the assignment of criteria that are relevant to the region. The Mediterranean fruit fly (Ceratitis capitata), frosty pod rot (Moniliophthora roreri) and the tomato leaf miner (Tuta absoluta), listed as top quarantine pest threats, were subsequently detected in the region. This exercise guided the authorities in advance to allocate resources and to develop response plans including capacity building for surveillance and detection of priority pests. This has demonstrated the significance and appropriateness of the multi-criteria decision approach to determine priority pest lists and prepare the region for development of better management practices.

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Methods Thu, 12 Oct 2023 10:43:56 +0300
Predation risk by largemouth bass modulates feeding functional responses of native and non-native crayfish https://neobiota.pensoft.net/article/108457/ NeoBiota 87: 191-212

DOI: 10.3897/neobiota.87.108457

Authors: Larissa Faria, Jean R. S. Vitule, Julian D. Olden

Abstract: Context-dependency is prevalent in nature, challenging our understanding and prediction of the potential ecological impacts of non-native species (NNS). The presence of a top predator, for example, can modify the foraging behaviour of an intermediate consumer, by means of non-consumptive effects. This raises the question of whether the fear of predation might modulate consumption rates of NNS, thus shaping the magnitude of ecological impacts. Here, we quantified the functional feeding responses of three non-native crayfish species – red swamp crayfish Procambarus clarkii, rusty crayfish Faxonius rusticus and virile crayfish Faxonius virilis – compared to the native analogue signal crayfish Pacifastacus leniusculus, considering the predation risk imposed by a top fish predator, the globally invasive largemouth bass Micropterus salmoides. We applied the comparative functional response (FR) approach using snails as prey and exposing crayfish to water containing predator and dietary chemical cues or not. All crayfish species presented a destabilising Type II FR, regardless of the presence of chemical cues. Predation risk resulted in significantly longer handling times or lower attack rates in non-native crayfish; however, no significant differences were observed in signal crayfish. We estimated per capita impacts for each species using the functional response ratio (FRR; attack rate divided by handling time). The FRR metric was lower for all crayfish species when exposed to predation risk. Rusty crayfish demonstrated the highest FRR in the absence of chemical cues, followed by signal crayfish, virile crayfish and red swamp crayfish. By contrast, the FRR of signal crayfish was nearly twice that of rusty crayfish and virile crayfish and ten times greater than red swamp crayfish when chemical cues were present. The latter result agrees with the well-recognised ecological impacts of signal crayfish throughout its globally-introduced range. This study demonstrates the importance of considering the non-consumptive effects of predators when quantifying the ecological impacts of intermediate non-native consumers on prey. The direction and magnitude of the modulating effects of predators have clear implications for our understanding of NNS impacts and the prioritisation of management actions.

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Research Article Wed, 4 Oct 2023 18:51:56 +0300
Capsaicin-treated bait is ineffective in deterring non-target mammals from trap disturbance during invasive lizard control https://neobiota.pensoft.net/article/102969/ NeoBiota 87: 103-120

DOI: 10.3897/neobiota.87.102969

Authors: Lance D. McBrayer, Daniel Haro, Michael Brennan, Bryan G. Falk, Amy A. Yackel Adams

Abstract: Excluding non-target species from invasive species control efforts can be challenging due to non-target attraction to trap structure, baits, and lures. Various methods have been used to deter non-target species from entering or disturbing traps including altered features (e.g., mesh size, trip mechanism, or entrances), staking traps, and chemical deterrents. Invasive populations of Argentine Black and White Tegu lizards (Salvator merianae) occur in several locations across Florida and Georgia, and there are ongoing trapping efforts to control them. At sites in Georgia, non-target mammals disturb most of the lizard traps (>80%), consume egg bait/lures, and thus reduce trap efficacy. In contrast, our Florida site has fewer problems with non-target mammals. Our goal was to quantify the efficacy of capsaicin-coated eggs, a known distasteful irritant to mammals, as a non-target bait deterrent in live traps set for tegus in both Georgia and Florida. We conducted feeding assays on three tegus and found that individuals readily consumed food coated in capsaicin. We then conducted a three-part, live trapping experiment to test 1) if trap disturbance by mammals habituated to eggs without capsaicin decreased when capsaicin-coated eggs were deployed in Georgia, 2) if mammals not habituated to eggs as bait (treated or untreated) disturbed live traps at the same rate as those habituated to eggs in Georgia, and 3) if tegu capture rates were different when capsaicin treated eggs were deployed in Florida. In Georgia, we found that trap disturbance by non-target mammals did not decrease when capsaicin was applied to eggs in an area previously habituated to trapping with this bait nor when applied in a novel area. In Florida, we found no significant difference in tegu captures using capsaicin-treated vs. untreated bait. Tegus were tolerant of capsaicin, but capsaicin treated eggs did not reduce non-target mammal disturbance to traps. Therefore, removal of invasive populations could be problematic if methods to reduce trap disturbance by non-targets are not identified and deployed.

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Research Article Thu, 17 Aug 2023 11:01:05 +0300
Assessing the risk of invasion by a vineyard moth pest guild https://neobiota.pensoft.net/article/100579/ NeoBiota 86: 169-191

DOI: 10.3897/neobiota.86.100579

Authors: Hector Zumbado-Ulate, Tyler E. Schartel, Gregory S. Simmons, Matthew P. Daugherty

Abstract: Biological invasions are most effectively managed when identified in their early stages, which often hinges on robust surveillance programs. The recent invasion of the European grapevine moth (Lobesia botrana) in California suggests that viticultural areas in the western United States may face severe economic consequences from this and other Tortricid and Pyralid moth species if they were to establish. To gain insights into the risk these grapevine pests pose, we used occurrence records for L. botrana and four other moths native to Europe or the eastern United States and selected environmental variables to predict the extent of climatically suitable areas and potential pest co-occurrence along the West Coast of the United States. A suite of models was generated using MaxEnt with species-specific tuning of model settings. Overall, the results confirmed high suitability for L. botrana to establish across much of the study region, driven largely by high monthly variability in precipitation and low elevation. Two species were predicted to have intermediate suitability to establish over the study region (i.e., grape tortrix moth, Argyrotaenia ljungiana; grape berry moth, Paralobesia viteana), while two others had low suitability (i.e., European grape berry moth, Eupoecilia ambiguella; Christmas berry webworm, Cryptoblabes gnidiella). The highest predicted potential for co-occurrence was between L. botrana and P. viteana, accounting for 19% of the total viticulture area, followed by L. botrana and A. ljungiana for 11% of the study area. These results may help with the optimization of surveillance efforts by indicating which species or areas should be prioritized for the deployment of invasive pest detection programs with pheromone traps. Indeed, given the apparent potential for co-occurrence of multiple moth pests in certain areas, our results may inform where single or multi-lure traps should be deployed as a more cost-efficient monitoring tool.

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Research Article Thu, 20 Jul 2023 14:52:22 +0300
lydemapr: an R package to track the spread of the invasive spotted lanternfly (Lycorma delicatula, White 1845) (Hemiptera, Fulgoridae) in the United States https://neobiota.pensoft.net/article/101471/ NeoBiota 86: 151-168

DOI: 10.3897/neobiota.86.101471

Authors: Sebastiano De Bona, Lawrence Barringer, Paul Kurtz, Jay Losiewicz, Gregory R. Parra, Matthew R. Helmus

Abstract: A crucial asset in the management of invasive species is the open-access sharing of data on the range of invaders and the progression of their spread. Such data should be current, comprehensive, consistent and standardised, to support reproducible and comparable forecasting efforts amongst multiple researchers and managers. Here, we present the lydemapr R package containing spatiotemporal data and mapping functions to visualise the current spread of the spotted lanternfly (Lycorma delicatula, White 1841) in the Western Hemisphere. The spotted lanternfly is a forest and agricultural pest in the eastern Mid-Atlantic Region of the U.S., where it was first discovered in 2014. As of 2023, it has been found in 14 states according to State and Federal Departments of Agriculture. However, the lack of easily accessible, fine-scale data on its spread hampers research and management efforts. We obtained multiple memoranda-of-understanding from several agencies and citizen-science projects, gaining access to their internal data on spotted lanternfly point observations. We then cleaned, harmonised, anonymised and combined the individual data sources into a single comprehensive dataset. The resulting dataset contains spatial data gridded at the 1 km2 resolution, with yearly information on the presence/absence of spotted lanternflies, establishment status and population density across 658,390 observations. The lydemapr package will aid researchers, managers and the public in their understanding, modelling and managing of the spread of this invasive pest.

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R Package Thu, 20 Jul 2023 14:50:26 +0300
The relationship between naturalized alien and native plant species: insights from oceanic islands of the south-east Pacific over the last 200 years https://neobiota.pensoft.net/article/102661/ NeoBiota 86: 21-43

DOI: 10.3897/neobiota.86.102661

Authors: Luis Cáceres-Polgrossi, Maura Di Rico, Diego Parra, Hanno Seebens, Stephen D. Galvin, H. Juergen Boehmer

Abstract: Aim: The relationship between native and naturalized alien species has been widely studied, particularly across large geographic scales. However, our knowledge of the spatial and temporal variations of their relationships is still limited, particularly for remote oceanic islands such as those of the south-east Pacific and across islands and archipelagos. In this study, we aim to assess the relationships between native and naturalized alien species by analyzing their current patterns of species-area relationships at different spatial scales, in addition to temporal variations in species richness, over the last 200 years. Area: One island (Rapa Nui) and two archipelagos (Juan Fernandez and Desventuradas Islands) comprising a total of 11 oceanic islands of the south-east Pacific (OISEP). Methods: We assembled the most comprehensive dataset of the vascular flora of the OISEP from currently available island flora checklists and updated with recent publications. Each plant species was classified as being native or naturalized alien. We examined temporal changes by estimating species richness, naturalization rates and naturalized-to-native ratios over time based on the first collection year of each naturalized alien species. Then, we determined the best shape of naturalized alien species richness accumulation over time by contrasting the fit of lineal, exponential, sigmoidal and Weibull regressions. Finally, we analyzed the relationships between native and naturalized species firstly at the inter-archipelagic scale by fitting island species-area relationship models and secondly at the island scale by performing ranged major axis regression analysis on residual values. Results: The OISEP flora dataset contained 674 species of which 282 were native and 392 were naturalized alien. Native island species-area relationships were similar to those of the naturalized alien species. Naturalized alien species richness increased notably through time with two clear peaks in 1950 and 2000. A Weibull regression and an exponential shape over time were the most appropriate fits for naturalized alien species richness accumulations at the inter-archipelagic scale, which further emphasizes the notable increase in naturalized alien species richness experienced in the timeframe examined here. Main conclusions: The relationship between naturalized alien species richness and native species richness was found to be independent of the geographic scale. The number of naturalized alien species clearly exceeded the number of native species on most islands but also for the whole OISEP. The accumulation of newly detected naturalized alien species does not show any sign of saturation and it is likely that new species will arrive in the future. Increased efforts on monitoring, prevention and biosecurity are needed to halt biological invasions on these unique island ecosystems.

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Research Article Fri, 7 Jul 2023 10:08:24 +0300
Myrtus communis in Europe threatened by the pandemic and South African strains of the myrtle rust pathogen Austropuccinia psidii (Sphaerophragmiaceae, Pucciniales) https://neobiota.pensoft.net/article/95823/ NeoBiota 84: 41-46

DOI: 10.3897/neobiota.84.95823

Authors: Trudy Paap, Alberto Santini, Carlos A. Rodas, Ginna M. Granados, Francesco Pecori, Michael J. Wingfield

Abstract: Austropuccinia psidii, the causal agent of myrtle rust, has emerged as a significant threat to Myrtaceae in planted and natural woody ecosystems. The first detection of A. puccinia in South Africa was from severely infected ornamental Myrtus communis. This raised concern that M. communis, the sole Myrtaceae species native to Europe and an important component of vegetation in Mediterranean regions, could be threatened by the rust. In light of the potential threat to this unique species, seed was collected from 12 Italian provenances of M. communis, including mainland and island (Sardinia and Sicily) populations. We assessed the susceptibility of these provenances to both the pandemic and South African strains of A. psidii. In Colombia, where the pandemic strain of A. psidii is native, seedlings rapidly became infected by natural inoculum. In South Africa, a preliminary screening of seedlings by artificial inoculation with a single-uredinium isolate produced high levels of disease. Finally, plants of each of the 12 provenances were planted and monitored in Florence, Italy. To date, these showed no signs of disease, but will continue to be monitored. This study highlights the significant threat that both the pandemic and South African strains of A. puccinia pose to M. communis in Europe.

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Short Communication Thu, 18 May 2023 18:00:03 +0300
Closely related invasive species may be controlled by the same demographic life stages https://neobiota.pensoft.net/article/95127/ NeoBiota 82: 189-207

DOI: 10.3897/neobiota.82.95127

Authors: Jane Molofsky, Dominik Thom, Stephen R. Keller, Lindsey R. Milbrath

Abstract: Invasive species that are closely related to each other may have similar population dynamics and, therefore, be controlled by targeting similar life stages. We studied two invasive knapweed species, spotted knapweed (Centaurea stoebe subsp. micranthos) and the hybrid meadow knapweed complex (Centaurea × moncktonii) in New York, USA, to determine their individual population growth rates (λ) across several sites over three years. Both knapweed species had growth rates that were greater than 1 (spotted knapweed λ ranged from 1.005–1.440; meadow knapweed λ ranged from 1.541–2.408), but there was high variability between years and sites. One study population of meadow knapweed was composed primarily of individuals of black knapweed ancestry (C. nigra), a species that, while introduced, is not invasive. For this population, the projected dynamics were stable (λ approximately 1). Elasticity analysis showed that the flowering-to-flowering stage contributed the most to population growth rate for six of seven sites and three additional transitions were also influential for four of seven sites of spotted and meadow knapweed: the seedling-to-vegetative stage, vegetative-to-flowering stage and flowering-to-seedling stage. We simulated how increasing vital rates would affect population growth and found that both spotted and meadow knapweed followed the same pattern. The vital rate of established seedlings maturing to flowering plants had the greatest effect on population growth, followed by the survival of new and established seedlings. In all cases, the responses were non-linear, with small initial changes having a large effect. Increases in the vital rates of later stages also tended to have a positive effect on growth rate, but the effects were more modest. Although the sensitivity analysis indicated that early vital rates had the largest effect on population growth, targeting these stages is not practical for management. Rather, reducing older life stage survival or delaying maturation of vegetative individuals would be more effective. The similarity between the population dynamics and how each life stage contributes to population growth provides support that protocols developed for one species should be effective for the other species with the caveat that any biological control agent should be directly tested on the target species before being utilised.

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Research Article Thu, 2 Mar 2023 18:32:05 +0200
Genetic relationships among laboratory lines of the egg parasitoid Trissolcus japonicus from native and adventive populations https://neobiota.pensoft.net/article/97881/ NeoBiota 82: 145-161

DOI: 10.3897/neobiota.82.97881

Authors: Paul K. Abram, Tyler D. Nelson, Valerie Marshall, Tara D. Gariepy, Tim Haye, Jinping Zhang, Tracy Hueppelsheuser, Susanna Acheampong, Chandra E. Moffat

Abstract: Candidate biological control agents of invasive insect pests are increasingly being found in new geographic regions as a result of unintentional introductions. However, testing the degree of genetic differentiation among adventive and native-range populations of these agents is rarely done. We used reduced-representation sequencing of genomic DNA to investigate the relationships among laboratory lines of Trissolcus japonicus (Ashmead) (Hymenoptera, Scelionidae), an egg parasitoid and biological control agent of the brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera, Pentatomidae). We compared sequences from multiple adventive populations in North America (Canada, USA) and Europe (Switzerland) with populations sourced from part of its native range in China. We found considerably more genetic variation among lines sourced from adventive populations than among those within native populations. In the Pacific Northwest of North America (British Columbia, Canada and Washington State, USA), we found preliminary evidence of three distinct genetic clusters, two of which were highly dissimilar from all other lines we genotyped. In contrast, we found that other adventive lines with close geographic proximity (two from Ontario, Canada, three from Switzerland) had limited genetic variation. These findings provide a basis for testing biological differences among lines that will inform their use as biological control agents, and provide evidence to support a hypothesis of several independent introductions of T. japonicus in western North America from different source areas.

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Short Communication Mon, 27 Feb 2023 10:55:14 +0200
Genetic analyses reveal a complex introduction history of the globally invasive tree Acacia longifolia https://neobiota.pensoft.net/article/87455/ NeoBiota 82: 89-117

DOI: 10.3897/neobiota.82.87455

Authors: Sara Vicente, Helena Trindade, Cristina Máguas, Johannes J. Le Roux

Abstract: Acacia longifolia (Sydney golden wattle) is considered one of the most problematic plant invaders in Mediterranean-type ecosystems. In this study, we investigate the species’ invasion history by comparing the genetic diversity and structure of native (Australia) and several invasive range (Brazil, Portugal, South Africa, Spain, and Uruguay) populations and by modelling different introduction scenarios using these data. We sampled 272 A. longifolia individuals – 126 from different invasive ranges and 146 from the native range – from 41 populations. We genotyped all individuals at four chloroplast and 12 nuclear microsatellite markers. From these data we calculated diversity metrics, identified chloroplast haplotypes, and estimated population genetic structure based on Bayesian assignment tests. We used Approximate Bayesian Computation (ABC) models to infer the likely introduction history into each invaded country. In Australia, population genetic structure of A. longifolia appears to be strongly shaped by the Bass Strait and we identified two genetic clusters largely corresponding to mainland Australian and Tasmanian populations. We found invasive populations to represent a mixture of these clusters. Similar levels of genetic diversity were present in native and invasive ranges, indicating that invasive populations did not go through a genetic bottleneck. Bayesian assignment tests and chloroplast haplotype frequencies further suggested a secondary introduction event between South Africa and Portugal. However, ABC analyses could not confidently identify the native source(s) of invasive populations in these two countries, probably due to the known high propagule pressure that accompanied these introductions. ABC analyses identified Tasmania as the likely source of invasive populations in Brazil and Uruguay. A definitive native source for Spanish populations could also not be identified. This study shows that tracing the introduction history of A. longifolia is difficult, most likely because of the complexity associated with the extensive movement of the species around the world. Our findings should be considered when planning management and control efforts, such as biological control, in some invaded regions.

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Research Article Tue, 21 Feb 2023 19:30:03 +0200
Population level interactions between an invasive woodwasp, an invasive nematode and a community of native parasitoids https://neobiota.pensoft.net/article/96599/ NeoBiota 82: 67-88

DOI: 10.3897/neobiota.82.96599

Authors: Saskya van Nouhuys, David C. Harris, Ann E. Hajek

Abstract: Parasitic nematodes and hymenopteran parasitoids have been introduced and used extensively to control invasive Eurasian Sirex noctilio woodwasps in pine plantations in the Southern Hemisphere where no members of this community are native. Sirex noctilio has more recently invaded North America where Sirex-associated communities are native. Sirex noctilio and its parasitic nematode, Deladenus siricidicola, plus six native hymenopteran woodwasp parasitoids in New York and Pennsylvania, were sampled from 204 pines in 2011–2019. Sirex noctilio had become the most common woodwasp in this region and the native parasitoids associated with the native woodwasps had expanded their host ranges to use this invader. We investigated the distributions of these species among occupied trees and the interactions between S. noctilio and natural enemies as well as among the natural enemies. Sirex noctilio were strongly aggregated, with a few of the occupied trees hosting hundreds of woodwasps. Nematode parasitism was positively associated with S. noctilio density, and negatively associated with the density of rhyssine parasitoids. Parasitism by the parasitoid Ibalia leucospoides was positively associated with host (S. noctilio) density, while parasitism by the rhyssine parasitoids was negatively associated with density of S. noctilio. Thus, most S. noctilio come from a few attacked trees in a forest, and S. noctilio from those high-density trees experienced high parasitism by both the invasive nematode and the most abundant native parasitoid, I. l. ensiger. There is little evidence for direct competition between the nematodes and parasitoids. The negative association occurring between rhyssine parasitoids and I. l. ensiger suggests rhyssines may suffer from competition with I. l. ensiger which parasitize the host at an earlier life stage. In addition to direct competition with the native woodwasp Sirex nigricornis for suitable larval habitat within weakened trees, the large S. noctilio population increases the parasitoid and nematode populations, which may increase parasitism of S. nigricornis.

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Research Article Thu, 9 Feb 2023 17:42:00 +0200
Genetic diversity and structure of Crupina vulgaris (common crupina): a noxious rangeland weed of the western United States https://neobiota.pensoft.net/article/90229/ NeoBiota 82: 57-66

DOI: 10.3897/neobiota.82.90229

Authors: John F. Gaskin, Nisha Chapagain, Mark Schwarzländer, Matthew A. Tancos, Natalie M. West

Abstract: Common crupina (Crupina vulgaris) is a federal noxious weed in the western USA that is currently the target of a classical biological control programme using the fungus Ramularia crupinae. We first identified and determined the location of populations of the two varieties of common crupina in the western United States and assessed the pattern of genetic diversity and structure of these populations. We found seven AFLP (Amplified Fragment Length Polymorphism) genotypes for 326 plants in 17 populations. AFLP genotypes correlated with two taxa, either C. vulgaris var. vulgaris or C. vulgaris var. brachypappa. This annual species is outcrossing, but relies on selfing when pollination does not occur, which may explain why less than 1% of the genetic variation is within populations. We found strong population genetic structuring and can typically predict genotype or variety for a given location. Researchers and managers will be able to predict and survey for differential efficacy of R. crupinae on the different genotypes and varieties during initial biological control field releases, thereby increasing the likelihood of successful biocontrol establishment and impact.

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Research Article Mon, 6 Feb 2023 18:02:20 +0200
The TOP-100 most dangerous invasive alien species in Northern Eurasia: invasion trends and species distribution modelling https://neobiota.pensoft.net/article/96282/ NeoBiota 82: 23-56

DOI: 10.3897/neobiota.82.96282

Authors: Varos Petrosyan, Fedor Osipov, Irina Feniova, Natalia Dergunova, Andrey Warshavsky, Lyudmila Khlyap, Andrew Dzialowski

Abstract: Northern Eurasia is extensive and includes terrestrial and aquatic ecosystems that cover several natural zones and access to the seas of three oceans. As a result, it has been invaded by numerous invasive alien species (IAS) over large temporal and spatial scales. The purpose of this research was to assess invasion trends and construct species distribution models for the Russian TOP-100 most dangerous IAS. Environmentally suitable regions for IAS were established based on alien species attribute databases, datasets of 169,709 species occurrence records (SOR) and raster layers of environmental variables using species distribution modelling (MaxEnt). The objectives of this research were to (1) create databases of SOR for the TOP-100 IAS in Russia; 2) determine pathways, residence time, donor regions and trends of invasions; (3) determine the main types of spatial distributions of invasive species and their relation to residence time; and (4) distinguish regions with the highest richness of IAS that have a strong impact on the terrestrial and aquatic ecosystems of Russia. We found that although species invasions date back over 400 years, the number of naturalized IAS has increased non-linearly over the past 76 years. The TOP-100 list is mainly represented by unintentionally introduced species (62%) which are characterized by different introduction pathways. Species occurrence records revealed that 56 IAS are distributed locally, 26 are distributed regionally and 18 are widespread in Russia. Species with local, regional or widespread distributions were characterized by residence times of 55, 126 or 190 years, respectively. We found that IAS with local distribution can expand their range into suitable regions more extensively (expected increase by 32%) than widespread species (expected increase by only 7%). The procedure of identifying hot/cold spots locations based on SOR allowed us to identify the Russian regions with the highest richness of IAS. Our results and the integrated database that we created provide a framework for studying IAS over large temporal and spatial scales that can be used in the development of management plans for dangerous IAS.

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Research Article Thu, 2 Feb 2023 18:31:44 +0200
Chelonian challenge: three alien species from North America are moving their reproductive boundaries in Central Europe https://neobiota.pensoft.net/article/87264/ NeoBiota 82: 1-21

DOI: 10.3897/neobiota.82.87264

Authors: Benno Tietz, Johannes Penner, Melita Vamberger

Abstract: Biological invasions by alien species have substantial economic impacts and are a major driver of the ongoing decline and loss of biodiversity. Through humans, the North American pond slider (Trachemys scripta) has acquired a global distribution over the last decades and is currently listed among the worst invasive reptile species. However, in more recent times, other freshwater chelonian species have increasingly been recorded far outside their native distribution ranges as well, not only on the same continent but also on others. Despite that, the impact of alien chelonians on their respective new ecosystems remains unclear. The long-term effects and severity of impacts of alien populations mostly depend on whether they ultimately succeed in establishing themselves. This is not entirely resolved for chelonians in Central Europe. To answer that, we investigated wild populations of three non-native chelonian species from North America in Germany (Pseudemys concinna, Graptemys pseudogeographica and Trachemys scripta) applying population genetic approaches. We revealed the successful reproduction of all three species in Germany and provide the very first record for the reproduction of P. concinna and G. pseudogeographica in a temperate continental climate zone outside their native distribution. Based on our unambiguous evidence of natural reproduction, we call for dedicated studies to verify how widespread established populations are and to investigate the existing and potential impacts of all three species in a range of ecosystems along a climatic gradient. Such data is urgently needed to revise the current risk assessments of non-native chelonians, especially in Central European countries.

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Research Article Wed, 1 Feb 2023 17:32:34 +0200
A bug’s tale: revealing the history, biogeography and ecological patterns of 500 years of insect invasions https://neobiota.pensoft.net/article/87362/ NeoBiota 81: 183-197

DOI: 10.3897/neobiota.81.87362

Authors: Daniela N. López, Eduardo Fuentes-Contreras, Cecilia Ruiz, Sandra Ide, Sergio A. Estay

Abstract: The arrival of Europeans to the Americas triggered a massive exchange of organisms on a continental scale. This exchange was accelerated by the rapid increase in the movement of people and goods during the 20th century. In Chile, scientific and technical literature contains hundreds of records of non-native insect species established in different parts of the territory, from the hyperarid Atacama Desert to the Magallanes Region. Here, we analyse temporal trends, taxonomic diversity, biogeographic origin and main impacts of these species on different sectors in Chile from the European arrival to the present. Our task includes a review of old records in museum catalogues, libraries, collections, expedition records and catalogues. Almost 600 species of non-native insects have been reported to be established in Chile. Introductions started with the very arrival of Europeans to the central valley of Chile and underwent a huge acceleration in the second half of the 20th century. The order Hemiptera was the most prevalent amongst non-native insects. Most species are linked to agriculture and forestry. Species are of Palearctic origin in more than 50% of the records. In terms of temporal trends, the rate of established non-native species shows an abrupt increase at the beginning of the 1950s. This change may be associated with the strong development in agriculture and forestry in Chile after World War II and the increase in intercontinental air traffic. We believe that the understanding of past patterns of introductions is an important component in the design of current policies to minimise the impact of invasive insects.

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Research Article Tue, 31 Jan 2023 19:01:02 +0200
Effects of the invasive leafy spurge (Euphorbia esula L.) on plant community structure are altered by management history https://neobiota.pensoft.net/article/89450/ NeoBiota 81: 157-182

DOI: 10.3897/neobiota.81.89450

Authors: Catherine Liu, Terava Groff, Erin Anderson, Charlotte Brown, James F. Cahill Jr, Lee Paulow, Jonathan A. Bennett

Abstract: Invasive species threaten biodiversity and ecosystem functioning, often causing changes in plant community composition and, thus, the functional traits of that community. Quantifying changes in traits can help us understand invasive species impacts on communities; however, both the invader and the plant community may be responding to the same environmental drivers. In North America, leafy spurge (Euphorbia esula L.) is a problematic invader that reduces plant diversity and forage production for livestock. Its documented effects on plant communities differ amongst studies, however, potentially due to differences in productivity or land management. To identify the potential effects of leafy spurge on plant communities, we quantified leafy spurge abundance, plant species richness, forage production, functional group composition and community weighted mean traits, intensively at a single site and extensively across ten sites differing in management. We then tested how leafy spurge abundance related to these variables as a function of site management activities. Leafy spurge abundance was consistently associated with fewer plant species, reduced forage production and more invasive grass. Community-weighted specific root length also consistently increased with leafy spurge abundance, suggesting that belowground competition may be important in determining co-existence with leafy spurge. Other changes were dependent on management. Native forbs were excluded as leafy spurge became more abundant, but only in grazed sites as these species were already absent from ungrazed sites. Taller plants better persisted in dense leafy spurge patches, but only in grazed sites, consistent with either facilitation of taller species via associational defences or competitive exclusion of shorter species in ungrazed sites and dense leafy spurge patches. These results show that, despite some emergent properties of invasion, management context can alter invasion impacts by causing changes in the plant community and its interactions with the invader.

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Research Article Fri, 27 Jan 2023 17:45:56 +0200
Status and distribution of an introduced population of European Goldfinches (Carduelis carduelis) in the western Great Lakes region of North America https://neobiota.pensoft.net/article/97736/ NeoBiota 81: 129-155

DOI: 10.3897/neobiota.81.97736

Authors: Julie A. Craves, Nicholas M. Anich

Abstract: Despite the importance of monitoring introduced species, reports of non-native birds are often initially dismissed by observers. This leads to serious information gaps about source localities, founding numbers, and growth and expansion of potential new populations. Here, we report on European Goldfinches in North America between 2001 and 2021, focusing on the western Great Lakes region. We compiled over 7000 records of European Goldfinches from multiple sources; over 3300 records were from the western Great Lakes. This species was initially reported widely in this region, but over time, birds were most consistently reported between Milwaukee, Wisconsin and Chicago, Illinois. They have been breeding in this area continuously since 2003 and the number of reported observations has increased in recent years. From our compiled records, we describe their distribution, breeding status, nesting phenology, and natural food sources. From import records, we provide evidence that the likely primary founding event of this population was release or escape from a cage bird importer in northern Illinois and provide information on possible origins. We briefly discuss possible ecological impacts. We highlight weaknesses in the way data on non-native species are currently collected and how it has impeded our ability to thoroughly reconstruct the recent history of this species in the western Great Lakes region. Formal study is needed on this population of European Goldfinches, including their potentially increasing population and range, ecology, and an evaluation of the potential effects on native ecosystems.

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Research Article Tue, 24 Jan 2023 18:46:52 +0200
Evidence of plant-soil feedback in South Texas grasslands associated with invasive Guinea grass https://neobiota.pensoft.net/article/86672/ NeoBiota 81: 33-51

DOI: 10.3897/neobiota.81.86672

Authors: Elizabeth A. Bowman, Robert M. Plowes, Lawrence E. Gilbert

Abstract: Plant-soil feedback (PSF) processes play an integral role in structuring plant communities. In native grasslands, PSF has a largely negative or stabilizing effect on plant growth contributing to species coexistence and succession, but perturbations to a system can alter PSF, leading to long-term changes. Through changes to soil abiotic and biotic properties, invasion by non-native plants has a strong impact on belowground processes with broad shifts in historical PSFs. Guinea grass, Megathyrsus maximus, an emerging invasive in South Texas, can efficiently exclude native plants in part due to its fast growth rate and high biomass accumulation, but its impacts on belowground processes are unknown. Here, we provide a first look at PSF processes in South Texas savannas currently undergoing invasion by Guinea grass. In this pilot study, we addressed the question of how the presence of the invasive M. maximus may alter PSF compared to uninvaded grasslands. Under greenhouse conditions, we assessed germination and growth of Guinea grass and the seed bank in soil collected from grasslands invaded and uninvaded by Guinea grass. We found that Guinea grass grown in soil from invaded grasslands grew taller and accumulated higher biomass than in soil from uninvaded grasslands. Plants grown from the seed bank were more species rich and abundant in soil from uninvaded grasslands but had higher biomass in soil from invaded grasslands. In South Texas savannas, we found evidence to support shifts in the direction of PSF processes in the presence of Guinea grass with positive feedback processes appearing to reinforce invasion and negative feedback processes possibly contributing to species coexistence in uninvaded grasslands. Future work is needed to determine the mechanisms behind the observed shifts in PSF and further explore the role PSF has in Guinea grass invasion.

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Research Article Thu, 19 Jan 2023 19:14:52 +0200
Burmese pythons in Florida: A synthesis of biology, impacts, and management tools https://neobiota.pensoft.net/article/90439/ NeoBiota 80: 1-119

DOI: 10.3897/neobiota.80.90439

Authors: Jacquelyn C. Guzy, Bryan G. Falk, Brian J. Smith, John David Willson, Robert N. Reed, Nicholas G. Aumen, Michael L. Avery, Ian A. Bartoszek, Earl Campbell, Michael S. Cherkiss, Natalie M. Claunch, Andrea F. Currylow, Tylan Dean, Jeremy Dixon, Richard Engeman, Sarah Funck, Rebekah Gibble, Kodiak C. Hengstebeck, John S. Humphrey, Margaret E. Hunter, Jillian M. Josimovich, Jennifer Ketterlin, Michael Kirkland, Frank J. Mazzotti, Robert McCleery, Melissa A. Miller, Matthew McCollister, M. Rockwell Parker, Shannon E. Pittman, Michael Rochford, Christina Romagosa, Art Roybal, Ray W. Snow, McKayla M. Spencer, J. Hardin Waddle, Amy A. Yackel Adams, Kristen M. Hart

Abstract: Burmese pythons (Python molurus bivittatus) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive Burmese pythons. We describe existing control tools and review challenges to productive research, identifying key knowledge gaps that would improve future research and decision making for python control.

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Review Article Tue, 10 Jan 2023 19:51:45 +0200
Low genetic diversity in a widespread whistling alien: A comparison of Eleutherodactylus johnstonei Barbour, 1914 (Eleutherodactylidae) and congeners in native and introduced ranges https://neobiota.pensoft.net/article/86778/ NeoBiota 79: 31-50

DOI: 10.3897/neobiota.79.86778

Authors: Franziska Leonhardt, Clara Arranz Aveces, Anke Müller, Baptiste Angin, Mathieu Jegu, Pius Haynes, Raffael Ernst

Abstract: There is no clear empirical evidence to support the general assumption that genetic diversity favours successful invasions. Many invading species disperse and establish successfully despite low genetic diversity, a phenomenon known as the genetic paradox of biological invasion. Model systems that allow comparison of genetic patterns between exotic and native source populations are still scarce. This is particularly true for amphibians. Here we compare genetic patterns of the widely introduced Johnstone’s Whistling Frog, Eleutherodactylus johnstonei, with its successful alien congener E. antillensis and the single island endemic E. portoricensis. Genetic diversity and population differentiation in native and introduced populations of the three taxa were inferred from mitochondrial D-loop sequences (235 bp). Our results reveal that exotic populations of the two alien taxa, E. johnstonei and E. antillensis, are not only genetically impoverished due to founder effects, but that, moreover, their native range source-populations exhibit low genetic diversity and inter-population differentiation in the first place. Populations of the endemic E. portoricensis, on the other hand, are genetically more diverse and show marked inter-population differentiation. These observed genetic patterns are consistent with geological processes and invasion histories. We argue that the establishment success of the alien taxa in our model system is better explained by ecological factors and anthropogenic drivers than by genetic diversity. As these factors provide more parsimonious explanations, they should be given priority in management decisions. However, molecular studies with higher resolution are needed to fully test possible genetic and epigenetic components that could promote the invasion process.

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Research Article Fri, 23 Dec 2022 13:52:14 +0200
Size distribution and reproductive phenology of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA https://neobiota.pensoft.net/article/93788/ NeoBiota 78: 129-158

DOI: 10.3897/neobiota.78.93788

Authors: Andrea F. Currylow, Bryan G. Falk, Amy A. Yackel Adams, Christina M. Romagosa, Jillian M. Josimovich, Michael R. Rochford, Michael S. Cherkiss, Melia G. Nafus, Kristen M. Hart, Frank J. Mazzotti, Ray W. Snow, Robert N. Reed

Abstract: The design of successful invasive species control programs is often hindered by the absence of basic demographic data on the targeted population. Establishment of invasive Burmese pythons (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida USA has led to local precipitous declines (> 90%) of mesomammal populations and is also a major threat to native populations of reptiles and birds. Efforts to control this species are ongoing but are hampered by the lack of access to and information on the expected biological patterns of pythons in southern Florida. We present data from more than 4,000 wild Burmese pythons that were removed in southern Florida over 26 years (1995–2021), the most robust dataset representing this invasive population to date. We used these data to characterize Burmese python size distribution, size at maturity, clutch size, and seasonal demographic and reproductive trends. We broadened the previously described size ranges by sex and, based on our newly defined size-stage classes, showed that males are smaller than females at sexual maturity, confirmed a positive correlation between maternal body size and potential clutch size, and developed predictive equations to facilitate demographic predictions. We also refined the annual breeding season (approx.100 days December into March), oviposition timing (May), and hatchling emergence and dispersal period (July through October) using correlations of capture morphometrics with observations of seasonal gonadal recrudescence (resurgence) and regression. Determination of reproductive output and timing can inform population models and help managers arrest population growth by targeting key aspects of python life history. These results define characteristics of the species in Florida and provide an enhanced understanding of the ecology and reproductive biology of Burmese pythons in their invasive Everglades range.

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Research Article Wed, 23 Nov 2022 20:07:41 +0200
Population genetics of an invasive mosquito vector, Aedes albopictus in the Northeastern USA https://neobiota.pensoft.net/article/84986/ NeoBiota 78: 99-127

DOI: 10.3897/neobiota.78.84986

Authors: Andrea Gloria-Soria, Talya Shragai, Alexander T. Ciota, Todd B. Duval, Barry W. Alto, Ademir J. Martins, Kathleen M. Westby, Kim A. Medley, Isik Unlu, Scott R. Campbell, Malgorzata Kawalkowski, Yoshio Tsuda, Yukiko Higa, Nicholas Indelicato, Paul T. Leisnham, Adalgisa Caccone, Philip M. Armstrong

Abstract: The Asian tiger mosquito (Aedes albopictus) arrived in the USA in the 1980’s and rapidly spread throughout eastern USA within a decade. The predicted northern edge of its overwintering distribution on the East Coast of the USA roughly falls across New York, Connecticut, and Massachusetts, where the species has been recorded as early as 2000. It is unclear whether Ae. albopictus populations have become established and survive the cold winters in these areas or are recolonized every year. We genotyped and analyzed populations of Ae. albopictus from the northeast USA using 15 microsatellite markers and compared them with other populations across the country and to representatives of the major global genetic clades to investigate their connectivity and stability. Founder effects or bottlenecks were rare at the northern range of the Ae. albopictus distribution in the northeastern USA, with populations displaying high levels of genetic diversity and connectivity along the East Coast. There is no evidence of population turnover in Connecticut during the course of three consecutive years, with consistent genetic structure throughout this period. Overall, these results support the presence of established populations of Ae. albopictus in New York, Connecticut, and Massachusetts, successfully overwintering and migrating in large numbers. Given the stability and interconnectedness of these populations, Ae. albopictus has the potential to continue to proliferate and expand its range northward under mean warming conditions of climate change. Efforts to control Ae. albopictus in these areas should thus focus on vector suppression rather than eradication strategies, as local populations have become firmly established and are expected to reemerge every summer.

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Research Article Wed, 23 Nov 2022 20:07:18 +0200
The invasiveness of Guinea grass (Megathyrsus maximus) is characterized by habitat and differing herbivore assemblages in its native and invaded range https://neobiota.pensoft.net/article/87069/ NeoBiota 78: 25-44

DOI: 10.3897/neobiota.78.87069

Authors: Aaron C. Rhodes, Robert M. Plowes, Dino J. Martins, Ivy Ng’Iru, Lawrence E. Gilbert

Abstract: A significant challenge of global change is the human-mediated movement of pasture grasses and their subsequent impact on ecosystem processes when they become invasive. We must understand invasive grass ecology and their natural enemies in native and introduced ranges to mitigate these impacts. Guinea grass (Megathyrsus maximus) is a pantropically introduced pasture grass that escapes intended areas and invades native ecosystems – threatening biodiversity and ecosystem function. The success of invasive plants has often been attributed to ecological release from stressors, including natural enemies and resource availability. Our objective was to assess Guinea grass functional traits across three different habitat types in native and invaded ranges by documenting ungulate and arthropod abundance, diversity, and feeding guilds. Guinea grass functional traits were assessed in three habitat types: grassland, riparian, and woody thickets around nitrogen-fixing Prosopis glandulosa in its introduced range in Texas, USA, and Senegalia mellifera in its native range in Kenya. We characterized Guinea grass functional traits by measuring plant height, cover, biomass, root-to-shoot ratios, and reproductive traits. We then examined the phytophagous arthropod and ungulate abundance and feeding guild diversity across the three habitat types. We hypothesized that functional trait expression related to invasiveness would be associated with Guinea grass in its introduced range. Also, we hypothesized that the abundance and diversity of phytophagous arthropods and ungulates would be lower in the invaded range. Finally, we hypothesized that Guinea grass functional traits would differ between the three habitat types, given the habitat types’ innate differences in resource availability. We found that Guinea grass was 2.5 times taller and 3.3 times more productive and covered 2.5 times more area in its invaded versus native ranges. Introduced Guinea grass had higher reproduction rates with 2.5 times more reproductive tillers, while habitat type drove vegetative reproduction with 15 times more stoloniferous establishment in wooded and riparian sites than grasslands. Texan ungulate communities were less species-rich, less functionally diverse, and less abundant than the Kenyan ungulate community. The phytophagous arthropod diversity on plants was twice as high on Kenyan Guinea grass than on Texan Guinea grass. Total arthropod family richness was nearly double, with 15 families represented in Kenya and 8 in Texas. These results suggest that Guinea grass has escaped a rich assemblage of arthropods and ungulates and likely explains some of its spread in introduced ranges. This study demonstrates how the invasive success of Guinea grass can be understood in terms of its competitive ability and interaction with natural enemies in the introduced and native ranges and may inform future biological control.

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Research Article Fri, 11 Nov 2022 12:14:12 +0200
Variation in plant traits and phylogenetic structure associated with native and nonnative species in an industrialized flora https://neobiota.pensoft.net/article/87307/ NeoBiota 77: 101-123

DOI: 10.3897/neobiota.77.87307

Authors: Samantha J. Worthy, Travis D. Marsico, Rima D. Lucardi, Lauren E. Whitehurst, Kevin S. Burgess

Abstract: Industrialized sites are hotspots for nonnative species because of continuous anthropogenic disturbance and nonnative propagule rain resulting from hitchhikers exchanged through global trade. Investigating plant traits and the phylogenetic structure of species at initial ports of entry can contribute to our understanding of how species are introduced to, assembled into, and survive at industrialized sites, which can also inform how susceptible these sites are to nonnative plant invasions. To compare native and nonnative species, we asked three questions: 1) Are plant traits differentially associated with species nativity (native versus nonnative)? (2) Do these traits have phylogenetic signals? and (3) What is the phylogenetic structure of each trait for native and nonnative species? We collected, identified, and vouchered 170 angiosperm species within the Garden City Terminal at the Port of Savannah, Georgia, USA, the largest container terminal in North America. Species nativity was derived from the literature, as were traits of pollination syndrome, dispersal syndrome, duration, and growth habit. Pearson’s Chi-squared tests were used to determine if traits were differentially associated with species nativity. Phylogenetic signal, along with mean pairwise distance (MPD) and mean nearest taxon distance (MNTD), were used to assess the degree of phylogenetic relatedness of native and nonnative species with each trait. Nonnative species showed a significant association with multiple pollination syndromes. Native species were significantly associated with perennial duration and zoophily pollination syndrome. All traits possessed a phylogenetic signal, and the anemophily pollination syndrome was significantly clustered for both native and nonnative species. Still, most other traits differed in their phylogenetic structure pattern based on the nativity. Overall, findings suggest that the environment is filtering for native and nonnative species that possess traits promoting introduction and survival at this industrialized point-of-entry. They also suggest that nonnative species trait differences partition available niches that promote their introduction to the site. More research is needed at industrialized sites to inventory and monitor the floristic community, investigate the establishment and spread probabilities of nonnative species, and prevent and mitigate nonnative species risks and impacts.

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Research Article Mon, 31 Oct 2022 09:49:55 +0200
Regional models do not outperform continental models for invasive species https://neobiota.pensoft.net/article/86364/ NeoBiota 77: 1-22

DOI: 10.3897/neobiota.77.86364

Authors: Catherine S. Jarnevich, Helen R. Sofaer, Pairsa Belamaric, Peder Engelstad

Abstract: Aim: Species distribution models can guide invasive species prevention and management by characterizing invasion risk across space. However, extrapolation and transferability issues pose challenges for developing useful models for invasive species. Previous work has emphasized the importance of including all available occurrences in model estimation, but managers attuned to local processes may be skeptical of models based on a broad spatial extent if they suspect the captured responses reflect those of other regions where data are more numerous. We asked whether species distribution models for invasive plants performed better when developed at national versus regional extents. Location: Continental United States. Methods: We developed ensembles of species distribution models trained nationally, on sagebrush habitat, or on sagebrush habitat within three ecoregions (Great Basin, eastern sagebrush, and Great Plains) for nine invasive plants of interest for early detection and rapid response at local or regional scales. We compared the performance of national versus regional models using spatially independent withheld test data from each of the three ecoregions. Results: We found that models trained using a national spatial extent tended to perform better than regionally trained models. Regional models did not outperform national ones even when considerable occurrence data were available for model estimation within the focal region. Information was often unavailable to fit informative regional models precisely in those areas of greatest interest for early detection and rapid response. Main conclusions: Habitat suitability models for invasive plant species trained at a continental extent can reduce extrapolation while maximizing information on species’ responses to environmental variation. Standard modeling methods can capture spatially varying limiting factors, while regional or hierarchical models may only be advantageous when populations differ in their responses to environmental conditions, a condition expected to be relatively rare at the expanding boundaries of invasive species’ distributions.

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Research Article Tue, 4 Oct 2022 10:38:26 +0300
Defining invasive species and demonstrating impacts of biological invasions: a scientometric analysis of studies on invasive alien plants in Brazil over the past 20 years https://neobiota.pensoft.net/article/85881/ NeoBiota 76: 13-24

DOI: 10.3897/neobiota.76.85881

Authors: Maria Cecilia Fachinello, Jair Hernando Castro Romero, Wagner Antonio Chiba de Castro

Abstract: Despite biological invasions being widely recognised as an important driver of environmental change, lack of consensus regarding the definition of invasive alien species (IAS) and vagueness around the demonstration of their impacts limits knowledge and research in this field. In this study, a scientometric approach was used to analyse academic documents published between 2002 and 2021 in three databases with reference to invasive alien plants in Brazil. Despite the growing body of scientific literature in the area, only 10% of the publications provided some definition of invasive species. Of the 398 publications analysed, 23.6% found some type of damage caused by the invader and, of these, only 5% addressed economic or social damage. Only 17% of the publications proposed a method for controlling and/or mitigating biological invasions. The absence of clear terminology and the lack of focus on impacts limits understanding of IAS of plants in Brazil. Based on the present findings, future studies on IAS of plants should move towards a consensus on the definition of biological invasion, as well as understand the impact caused by these species. In addition, it is recommended that further scientometric studies should guide future efforts to support objective measures for management and decision-making.

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Review Article Mon, 3 Oct 2022 18:55:02 +0300
From anti-science to environmental nihilism: the Fata Morgana of invasive species denialism https://neobiota.pensoft.net/article/90631/ NeoBiota 75: 39-56

DOI: 10.3897/neobiota.75.90631

Authors: Noelle G. Stratton, Nicholas E. Mandrak, Nicole Klenk

Abstract: Invasive species denialism (ISD) is a controversial and hitherto underexplored topic, particularly with regard to its potential impacts on stakeholder engagement in support of invasive species management and policy. We examined how ISD is framed within the Great Lakes invasive species community, as well as the impacts of excluding and including those perceived as denialists in engagement efforts. We interviewed key informants in the region to gain an understanding of their framings of ISD, as well as focus groups allowing participants to discuss the impacts of exclusion and inclusion of stakeholders during the engagement process. ISD discussions were organised into three framings: 1) invasive species denialism; 2) invasive species cynicism; 3) invasive species nihilism. Participants raised concerns about outright exclusion of stakeholders and offered recommendations for mitigation of the impacts of inclusion of proponents of ISD in during stakeholder engagement. Our results have shown that a better understanding of the different framings of ISD is crucial to improve communication with stakeholders and to better inform responses and mitigation efforts. The newly defined framings of invasive species cynicism and invasive species nihilism demonstrate that more targeted responses to specific forms of ISD are needed to improve stakeholder engagement outcomes.

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Research Article Thu, 1 Sep 2022 09:42:39 +0300
Comparing field-based management approaches for invasive Winter Heliotrope (Petasites pyrenaicus, Asteraceae) https://neobiota.pensoft.net/article/82673/ NeoBiota 74: 171-187

DOI: 10.3897/neobiota.74.82673

Authors: Daniel Jones, Mike S. Fowler, Sophie Hocking, Daniel Eastwood

Abstract: Winter Heliotrope (Petasites pyrenaicus, previously P. fragrans), is a persistent, rhizome-forming species found throughout the Mediterranean region and North Africa and is an Invasive Alien Plant (IAP) in the UK and Ireland. P. pyrenaicus excludes native flora by forming a dense, compact canopy that persists for much of the growing season, and is often found growing in rough ground, riparian areas and along communication routes, incurring significant management costs at sites of conservation interest. Our study describes the first field-based assessment of P. pyrenaicus control treatments, testing 12 physical and/or chemical treatments in replicated 1 m2 plots over four years and one chemical treatment over three years. Treatments focused on understanding phenology and resource allocation to exploit rhizome source-sink relationships in P. pyrenaicus. Multiple-stage glyphosate- and picloram-based treatments reduced leaf canopy cover to zero (%) over time, though no treatment completely eradicated P. pyrenaicus. When designing management strategies, effective P. pyrenaicus control may be achieved by a single annual soil and/or foliar application of picloram at 1.34 kg AE ha-1 in spring, or by a single annual foliar application of glyphosate in spring at 2.16 kg AE ha-1. Control is not improved by the addition of other herbicides or physical treatment methods, underlining the importance of these herbicides for perennial invasive plant management. This work confirms the importance of considering plant phenology, resource allocation and rhizome source-sink relationships, to increase treatment efficacy and reduce the environmental impacts associated with the management of P. pyrenaicus and other invasive, rhizome forming species.

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Research Article Wed, 27 Jul 2022 19:55:41 +0300
Scanning the horizon for invasive plant threats using a data-driven approach https://neobiota.pensoft.net/article/83312/ NeoBiota 74: 129-154

DOI: 10.3897/neobiota.74.83312

Authors: Amy E. Kendig, Susan Canavan, Patti J. Anderson, S. Luke Flory, Lyn A. Gettys, Doria R. Gordon, Basil V. Iannone III, John M. Kunzer, Tabitha Petri, Ian A. Pfingsten, Deah Lieurance

Abstract: Early detection and eradication of invasive plants are more cost-effective than managing well-established invasive plant populations and their impacts. However, there is high uncertainty around which taxa are likely to become invasive in a given area. Horizon scanning that combines a data-driven approach with rapid risk assessment and consensus building among experts can help identify invasion threats. We performed a horizon scan of potential invasive plant threats to Florida, USA—a state with a high influx of introduced species, conditions that are generally favorable for plant establishment, and a history of negative impacts from invasive plants. We began with an initial list of 2128 non-native plant taxa that are known invaders or crop pests. We built on previous invasive species horizon scans by developing data-based criteria to prioritize 100 taxa for rapid risk assessment. The semi-automated prioritization process included selecting taxa “on the horizon” (i.e., not yet in the target location and not on a noxious weed list) with climate matching, naturalization history, “weediness” record, and global commonness. We derived overall invasion risk scores with rapid risk assessment by evaluating the likelihood of each of the taxa arriving, establishing, and having an impact in Florida. Then, following a consensus-building discussion, we identified six plant taxa as high risk, with overall risk scores ranging from 75 to 100 out of a possible 125. The six taxa are globally distributed, easily transported to new areas, found in regions with climates similar to Florida’s, and can impact native plant communities, human health, or agriculture. Finally, we evaluated our initial and final lists for potential biases. Assessors tended to assign higher risk scores to taxa that had more available information. In addition, we identified biases towards four plant families and certain geographical regions of origin. Our horizon scan approach identified taxa conforming to metrics of high invasion risk and used a methodology refined for plants that can be applied to other locations.

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Research Article Fri, 15 Jul 2022 16:48:34 +0300
Words matter: a systematic review of communication in non-native aquatic species literature https://neobiota.pensoft.net/article/79942/ NeoBiota 74: 1-28

DOI: 10.3897/neobiota.74.79942

Authors: Elizabeth J. Golebie, Carena J. van Riper, Robert Arlinghaus, Megan Gaddy, Seoyeon Jang, Sophia Kochalski, Yichu Lu, Julian D. Olden, Richard Stedman, Cory Suski

Abstract: How scientists communicate can influence public viewpoints on invasive species. In the scientific literature, some invasion biologists adopt neutral language, while others use more loaded language, for example by emphasizing the devastating impacts of invasive species and outlining consequences for policy and practice. An evaluation of the use of language in the invasion biology literature does not exist, preventing us from understanding which frames are used and whether there are correlations between message framing in scientific papers and local environmental impacts associated with invasive species. Thus, we conducted a systematic literature review of 278 peer-reviewed articles published from 2008–2018 to understand communication styles adopted by social and natural scientists while reporting on aquatic non-native species research. Species-centered frames (45%) and human-centered frames (55%) were adopted to nearly equal degrees. Negative valence was dominant in that 81.3% of articles highlighted the negative risks and impacts of invasive species. Additionally, the use of terminology was found to broadly align with the stage of invasion, in that “invasive” was most commonly used except when the research was conducted at early stages of invasion, when “non-native” was most commonly used. Terminology use therefore enables readers of scientific papers to infer the status and severity of ongoing invasions. Given that science communication within the peer-reviewed literature affects public understanding of research outcomes, these findings provide an important point of reflection for researchers.

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Review Article Tue, 31 May 2022 18:53:58 +0300
A low-cost, durable, submersible light trap and customisable LED design for pelagic deployment and capture of fish parasite Salmincola sp. copepodids https://neobiota.pensoft.net/article/76515/ NeoBiota 73: 1-17

DOI: 10.3897/neobiota.73.76515

Authors: Christina A. Murphy, William Gerth, Travis Neal, Ivan Arismendi

Abstract: Documenting species invasions and assessments of ecological changes depend on detection. Here, we present a simple design of a plankton light trap with specific wavelength LEDs and modifications. We used PVC pipe to create standardised small, rigid, low-cost traps that can be deployed in lentic habitats. With a cost of under $30 US each, including lights and rechargeable batteries, our traps are affordable without the need for disposable chemical lights. These small traps rely on a vacuum to retain contents upon retrieval, eliminating complicated closing mechanisms and allowing bottom entry. Our design includes submersible LED lights that can withstand pressures of at least 5 atm. We expect that the included instructions for underwater light construction and rubber weights using sand may be broadly applicable. However, we designed and field-tested our traps focusing on the detection and capture of the infective copepodid lifestage of a freshwater parasitic copepod, Salmincola californiensis. This lifestage had previously only been observed by rearing in a laboratory setting and is of concern due to continued spread outside of its native range and detrimental impacts on salmonids, especially in freshwater reservoirs. We used a 445–450 nm wavelength LED light for capturing Salmincola copepodids, but the light design can be modified to any readily available LED and heat sink to attract other target organisms. In our case, the overall affordability of the trap and components allowed for the extensive trapping needed to capture and map the occurrence of rarely-observed species and lifestages, such as the copepodids of S. californiensis. In general, increasing the number of traps that can be deployed within or across sites can aid in the spatial comparisons of plankton distributions needed in studies of ecology and species life histories. Light traps may aid in the detection of introduced zooplankton, such as S. californiensis, outside of their native range and associated plankton community changes.

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Methods Thu, 28 Apr 2022 11:16:09 +0300
Network-based analysis reveals differences in plant assembly between the native and the invaded ranges https://neobiota.pensoft.net/article/72066/ NeoBiota 72: 157-181

DOI: 10.3897/neobiota.72.72066

Authors: Laura Del Rio-Hortega, Irene Martín-Forés, Isabel Castro, José M De Miguel, Belén Acosta-Gallo

Abstract: Associated with the introduction of alien species in a new area, interactions with other native species within the recipient community occur, reshaping the original community and resulting in a unique assemblage. Yet, the differences in community assemblage between native and invaded ranges remain unclear. Mediterranean grasslands provide an excellent scenario to study community assembly following transcontinental naturalisation of plant species. Here, we compared the community resemblance of plant communities in Mediterranean grasslands from both the native (Spain) and invaded (Chile) ranges. We used a novel approach, based on network analysis applied to co-occurrence analysis in plant communities, allowing us to study the co-existence of native and alien species in central Chile. This useful methodology is presented as a step forward in invasion ecology studies and conservation strategies. We found that community structure differed between the native and the invaded range, with alien species displaying a higher number of connections and, therefore, acting as keystones to sustain the structure within the invaded community. Alien species acting like keystones within the Chilean grassland communities might exacerbate the threat posed by biological invasions for the native biodiversity assets. Controlling the spread of the alien species identified here as keystones should help managing potential invasion in surrounding areas. Network analyses is a free, easy-to-implement and straightforward visual tool that can be widely used to reveal shifts in native communities and elucidate the role of multiple invaders into communities.

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Research Article Tue, 29 Mar 2022 16:47:56 +0300
Demography of an invading forest insect reunited with hosts and parasitoids from its native range https://neobiota.pensoft.net/article/75392/ NeoBiota 72: 81-107

DOI: 10.3897/neobiota.72.75392

Authors: Flora E. Krivak-Tetley, Jenna Sullivan-Stack, Jeff R. Garnas, Kelley E. Zylstra, Lars-Olaf Höger, María J. Lombardero, Andrew M. Liebhold, Matthew P. Ayres

Abstract: The Sirex woodwasp Sirex noctilio Fabricius (Hymenoptera: Siricidae), a widespread invasive pest of pines in the Southern Hemisphere, was first detected in North America in 2004. This study assessed the impacts of life history traits, host resistance and species interactions on the demography of S. noctilio in New York, Pennsylvania and Vermont, then compared key metrics to those found in the native range in Galicia, Spain. Many trees naturally attacked by S. noctilio in North America produced no adult woodwasps, with 5 of 38 infested trees (13%) sampled across six sites yielding 64% of emerging insects. Reproductive success was highest in the introduced host scots pine, Pinus sylvestris, but native red pine, Pinus resinosa, produced larger insects. Sirex noctilio required one or sometimes two years to develop and sex ratios were male biased, 1:2.98 ♀:♂. Body size and fecundity were highly variable, but generally lower than observed in non-native populations in the Southern Hemisphere. Hymenopteran parasitoids killed approximately 20% of S. noctilio larvae and 63% of emerging adults were colonized by the parasitic nematode Deladenus siricidicola, although no nematodes entered eggs. Demographic models suggested that S. noctilio in the northeastern USA have a higher potential for population growth than populations in the native range: estimated finite factor of increase, λ, was 4.17–4.52 (depending on tree species colonized), compared to λ = 1.57 in Spain.

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Research Article Fri, 25 Mar 2022 17:10:06 +0200
Using leaf functional traits to remotely detect Cytisus scoparius (Linnaeus) Link in endangered savannahs https://neobiota.pensoft.net/article/76573/ NeoBiota 71: 149-164

DOI: 10.3897/neobiota.71.76573

Authors: Paul W. Hacker, Nicholas C. Coops

Abstract: Identification of invasive plant species must be accurate and timely for management practices to be successful. Currently, Cytisus scoparius (Scotch broom) is expanding unmonitored across North America’s west coast, threatening established ecological processes and altering biodiversity. Remote detection of leaf functional traits presents opportunities to better understand the distribution of C. scoparius. This paper demonstrates the capacity for remotely sensed leaf functional traits to differentiate C. scoparius from other common plant species found in mixed grassland-woodland ecosystems at the leaf- and canopy-levels. Retrieval of leaf nitrogen percent, specifically, was found to be significantly higher in C. scoparius than each of the other 22 species sampled. These findings suggest that it may be possible to accurately detect introduced C. scoparius individuals using information collected from leaf and imaging spectroscopy at fine spatial resolutions.

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Research Article Fri, 11 Feb 2022 10:22:30 +0200
Predatory ability and abundance forecast the ecological impacts of two aquatic invasive species https://neobiota.pensoft.net/article/75711/ NeoBiota 71: 91-112

DOI: 10.3897/neobiota.71.75711

Authors: Emma M. DeRoy, Steven Crookes, Kyle Matheson, Ryan Scott, Cynthia H. McKenzie, Mhairi E. Alexander, Jaimie T. A. Dick, Hugh J. MacIsaac

Abstract: Characterising interspecific interaction strengths, combined with population abundances of prey and their novel predators, is critical to develop predictive invasion ecology. This is especially true of aquatic invasive species, which can pose a significant threat to the structure and stability of the ecosystems to which they are introduced. Here, we investigated consumer-resource dynamics of two globally-established aquatic invasive species, European green crab (Carcinus maenas) and brown trout (Salmo trutta). We explored the mediating effect of prey density on predatory impact in these invaders relative to functionally analogous native rock crab (Cancer irroratus) and Atlantic salmon (Salmo salar), respectively, feeding on shared prey (Mytilus sp. and Tenebrio molitor, respectively). We subsequently combined feeding rates with each predator’s regional abundance to forecast relative ecological impacts. All predators demonstrated potentially destabilising Type II functional responses towards prey, with native rock crab and invasive brown trout exhibiting greater per capita impacts relative to their trophic analogues. Functional Response Ratios (attack rates divided by handling times) were higher for both invasive species, reflecting greater overall per capita effects compared to natives. Impact projections that incorporated predator abundances with per capita effects predicted severe impacts by European green crabs. However, brown trout, despite possessing higher per capita effects than Atlantic salmon, are projected to have low impact owing to currently low abundances in the sampled watershed. Should brown trout density increase sixfold, we predict it would exert higher impact than Atlantic salmon. Such impact-forecasting metrics and methods are thus vital tools to assist in the determination of current and future adverse impacts associated with aquatic invasive species.

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Research Article Thu, 27 Jan 2022 09:49:29 +0200
Mate choice errors may contribute to slow spread of an invasive Eurasian longhorn beetle in North America https://neobiota.pensoft.net/article/72843/ NeoBiota 71: 71-89

DOI: 10.3897/neobiota.71.72843

Authors: Jennifer L. Anderson, Stephen B. Heard, Jon Sweeney, Deepa S. Pureswaran

Abstract: Tetropium fuscum (Coleoptera: Cerambycidae) is a Eurasian longhorn beetle and forest pest that first became invasive to Nova Scotia, Canada around 1990. In the time since its introduction, T. fuscum has spread only about 150 km from its point of introduction. In its invasive range, T. fuscum co-exists with its congener Tetropium cinnamopterum. Although they are ecologically similar species, T. fuscum tends to infest healthier trees and has a smaller host range than T. cinnamopterum. If they successfully interbreed, this could lead to hybrid individuals that are more problematic than either parent species. On the other hand, if T. fuscum can make mating errors in the field, but is not producing hybrid offspring, then this waste of mating resources could help explain the slow spread of T. fuscum in North America. We conducted no-choice and choice mating experiments between T. fuscum and T. cinnamopterum males and females and determined that both T. fuscum and T. cinnamopterum males make mate-choice errors with heterospecific females in a laboratory setting. Our results suggest that mating errors may play a role in the slow spread of T. fuscum in North America.

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Research Article Tue, 25 Jan 2022 10:46:46 +0200
Spatial dynamics of spotted lanternfly, Lycorma delicatula, invasion of the Northeastern United States https://neobiota.pensoft.net/article/67950/ NeoBiota 70: 23-42

DOI: 10.3897/neobiota.70.67950

Authors: Rachel T. Cook, Samuel F. Ward, Andrew M. Liebhold, Songlin Fei

Abstract: Spotted lanternfly (SLF), Lycorma delicatula (White) (Hemiptera: Fulgoridae), is a non-native planthopper that recently established in the Northeastern United States. Little is known about the spatial dynamics of its invasion and key drivers associated with its regional spread. Here, using field survey data from a total of 241,366 survey locations from 2014–2019 in the eastern USA, we quantified rates of SLF spread and modeled factors associated with the risk of SLF invasion. During the study period, SLF invasion appears to be associated with both short- and long-distance dispersal. On average, the number of newly invaded counties per year increased since initial discovery, with 0–14 long-distance dispersal events per year and median jump distances ranging from 55 to 92 km/year throughout the study period. Radial rates of spread, based on two of the three analysis methods applied, varied from 38.6 to 46.2 km/year. A Cox proportional hazards model suggested that risk of SLF invasion increased with a proxy for human-aided dispersal, human population per county. We anticipate that SLF will continue to spread via both long- and short-distance dispersals, especially via human activities. Efforts to manage SLF populations potentially could target human-mediated movement of SLF to reduce rates of spread.

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Research Article Mon, 6 Dec 2021 10:48:48 +0200
A perennial invader’s seed and rhizome differ in cold tolerance and apparent local adaptation https://neobiota.pensoft.net/article/64614/ NeoBiota 70: 1-21

DOI: 10.3897/neobiota.70.64614

Authors: Vasiliy T. Lakoba, Gregory E. Welbaum, John R. Seiler, Jacob N. Barney

Abstract: Extreme cold plays a key role in the range boundaries of plants. Winter survival is central to their persistence, but not all structures are equally susceptible to frost kill and, therefore, limiting to distributions. Furthermore, we expect intraspecific variation in cold tolerance both within and among tissue types. In a laboratory setting, we determined freezing tolerances of two overwintering propagule types – seeds and rhizomes – of the globally invasive Johnsongrass (Sorghum halepense), testing apparent emergence and electrolyte leakage as a proxy for cell death. We used 18 genotypes from agricultural and non-agricultural habitats spanning the climatic extremes occupied by Johnsongrass in the US. Single node rhizome fragments had an average LT90 of -5.1 °C with no significant variation based on home climate or ecotype. Seeds frozen at -85 °C suffered a decline in germinability to 10% from 25% at 22 °C. Population origin did not affect seed response to any temperature. However, non-agricultural seeds germinated more and faster than agricultural seeds from the coldest climates, with a reversed relationship among warmest origin seeds. Regardless of ecotype, seeds from the cold/dry and wet/warm sectors of Johnsongrass’s range germinated more and faster. Drastic differences in cold tolerance between seeds and rhizome and evidence for seeds’ local adaptation to land use and climate suggest that its spread is likely limited by winter rhizome survival, as well as adaptability of germination behavior to longer winters. These findings shed light on Johnsongrass’ dispersal dynamics and help identify future avenues for mechanistically understanding its range limitation.

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Research Article Tue, 16 Nov 2021 17:35:52 +0200
A global assessment of the potential distribution of naturalized and planted populations of the ornamental alien tree Schinus molle https://neobiota.pensoft.net/article/68572/ NeoBiota 68: 105-126

DOI: 10.3897/neobiota.68.68572

Authors: Jorge E. Ramírez-Albores, David M. Richardson, Valdir M. Stefenon, Gustavo A. Bizama, Marlín Pérez-Suárez, Ernesto I. Badano

Abstract: The Peruvian Peppertree (Schinus molle L.) is an evergreen tree native to semiarid environments of Peru and Bolivia in South America. This tree has been introduced and widely planted for ornamental and forestry purposes in several semiarid regions of the world because its seedlings are easily established and have a high survival rate; it also grows quickly, and it is tolerant of dry climates. We compared the global and regional niches of naturalized and planted populations of S. molle in order to examine the invasive stages and potential distribution of this species in four regions of the world. This work provides a novel approach for understanding the invasion dynamics of S. molle in these areas and elucidates the ecological processes that bring about such invasions. Most naturalized and planted populations were found to be in equilibrium with the environment. In its native range as well as in Australia and South Africa the models of the coverage area of habitat suitability for natural populations were the highest, whereas the coverage area of planted populations was lower. For planted populations in Australia and South Africa, a large percentage of predicted presences fell within sink populations. The invasion stages of S. molle vary across regions in its adventive range; this result may be attributable to residence time as well as climatic and anthropic factors that have contributed to the spread of populations.

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Research Article Tue, 21 Sep 2021 09:24:05 +0300
Economic costs of biological invasions within North America https://neobiota.pensoft.net/article/58038/ NeoBiota 67: 485-510

DOI: 10.3897/neobiota.67.58038

Authors: Robert Crystal-Ornelas, Emma J. Hudgins, Ross N. Cuthbert, Phillip J. Haubrock, Jean Fantle-Lepczyk, Elena Angulo, Andrew M. Kramer, Liliana Ballesteros-Mejia, Boris Leroy, Brian Leung, Eugenia López-López, Christophe Diagne, Franck Courchamp

Abstract: Invasive species can have severe impacts on ecosystems, economies, and human health. Though the economic impacts of invasions provide important foundations for management and policy, up-to-date syntheses of these impacts are lacking. To produce the most comprehensive estimate of invasive species costs within North America (including the Greater Antilles) to date, we synthesized economic impact data from the recently published InvaCost database. Here, we report that invasions have cost the North American economy at least US$ 1.26 trillion between 1960 and 2017. Economic costs have climbed over recent decades, averaging US$ 2 billion per year in the early 1960s to over US$ 26 billion per year in the 2010s. Of the countries within North America, the United States (US) had the highest recorded costs, even after controlling for research effort within each country ($5.81 billion per cost source in the US). Of the taxa and habitats that could be classified in our database, invasive vertebrates were associated with the greatest costs, with terrestrial habitats incurring the highest monetary impacts. In particular, invasive species cumulatively (from 1960–2017) cost the agriculture and forestry sectors US$ 527.07 billion and US$ 34.93 billion, respectively. Reporting issues (e.g., data quality or taxonomic granularity) prevented us from synthesizing data from all available studies. Furthermore, very few of the known invasive species in North America had reported economic costs. Therefore, while the costs to the North American economy are massive, our US$ 1.26 trillion estimate is likely very conservative. Accordingly, expanded and more rigorous economic cost reports are necessary to provide more comprehensive invasion impact estimates, and then support data-based management decisions and actions towards species invasions.

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Research Article Thu, 29 Jul 2021 18:55:19 +0300
Economic costs of invasive alien species in Mexico https://neobiota.pensoft.net/article/63846/ NeoBiota 67: 459-483

DOI: 10.3897/neobiota.67.63846

Authors: Axel Eduardo Rico-Sánchez, Phillip J. Haubrock, Ross N. Cuthbert, Elena Angulo, Liliana Ballesteros-Mejia, Eugenia López-López, Virginia G. Duboscq-Carra, Martín A. Nuñez, Christophe Diagne, Franck Courchamp

Abstract: Invasive alien species (IAS) are a leading driver of biodiversity loss worldwide, and have negative impacts on human societies. In most countries, available data on monetary costs of IAS are scarce, while being crucial for developing efficient management. In this study, we use available data collected from the first global assessment of economic costs of IAS (InvaCost) to quantify and describe the economic cost of invasions in Mexico. This description was made across a range of taxonomic, sectoral and temporal variables, and allowed us to identify knowledge gaps within these areas. Overall, costs of invasions in Mexico were estimated at US$ 5.33 billion (i.e., 109) ($MXN 100.84 billion) during the period from 1992 to 2019. Biological invasion costs were split relatively evenly between aquatic (US$ 1.16 billion; $MXN 21.95 billion) and terrestrial (US$ 1.17 billion; $MXN 22.14 billion) invaders, but semi-aquatic taxa dominated (US$ 2.99 billion; $MXN 56.57 billion), with costs from damages to resources four times higher than those from management of IAS (US$ 4.29 billion vs. US$ 1.04 billion; $MXN 81.17 billion vs $MXN 19.68 billion). The agriculture sector incurred the highest costs (US$ 1.01 billion; $MXN 19.1 billion), followed by fisheries (US$ 517.24 million; $MXN 9.79 billion), whilst most other costs simultaneously impacted mixed or unspecified sectors. When defined, costs to Mexican natural protected areas were mostly associated with management actions in terrestrial environments, and were incurred through official authorities via monitoring, control or eradication. On natural protected islands, mainly mammals were managed (i.e. rodents, cats and goats), to a total of US$ 3.99 million, while feral cows, fishes and plants were mostly managed in protected mainland areas, amounting to US$ 1.11 million in total. Pterygoplichthys sp. and Eichhornia crassipes caused the greatest reported costs in unprotected aquatic ecosystems in Mexico, and Bemisia tabaci to terrestrial systems. Although reported damages from invasions appeared to be fluctuating through time in Mexico, management spending has been increasing. These estimates, albeit conservative, underline the monetary pressure that invasions put on the Mexican economy, calling for urgent actions alongside comprehensive cost reporting in national states such as Mexico.

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Research Article Thu, 29 Jul 2021 18:55:18 +0300
The economic costs of biological invasions in Central and South America: a first regional assessment https://neobiota.pensoft.net/article/59193/ NeoBiota 67: 401-426

DOI: 10.3897/neobiota.67.59193

Authors: Gustavo Heringer, Elena Angulo, Liliana Ballesteros-Mejia, César Capinha, Franck Courchamp, Christophe Diagne, Virginia Gisela Duboscq-Carra, Martín Andrés Nuñez, Rafael Dudeque Zenni

Abstract: Invasive alien species are responsible for a high economic impact on many sectors worldwide. Nevertheless, there is a scarcity of studies assessing these impacts in Central and South America. Investigating costs of invasions is important to motivate and guide policy responses by increasing stakeholders’ awareness and identifying action priorities. Here, we used the InvaCost database to investigate (i) the geographical pattern of biological invasion costs across the region; (ii) the monetary expenditure across taxa and impacted sectors; and (iii) the taxa responsible for more than 50% of the costs (hyper-costly taxa) per impacted sector and type of costs. The total of reliable and observed costs reported for biological invasions in Central and South America was USD 102.5 billion between 1975 and 2020, but about 90% of the total costs were reported for only three countries (Brazil, Argentina and Colombia). Costs per species were associated with geographical regions (i.e., South America, Central America and Islands) and with the area of the countries in km2. Most of the expenses were associated with damage costs (97.8%), whereas multiple sectors (77.4%), agriculture (15%) and public and social welfare (4.2%) were the most impacted sectors. Aedes spp. was the hyper-costly taxon for the terrestrial environment (costs of USD 25 billion) and water hyacinth (Eichhornia crassipes) was the hyper-costly taxon for the aquatic environment (USD 179.9 million). Six taxa were classified as hyper-costly for at least one impacted sector and two taxa for at least one type of cost. In conclusion, invasive alien species caused billions of dollars of economic burden in Central and South America, mainly in large countries of South America. Costs caused by invasive alien species were unevenly distributed across countries, impacted sectors, types of costs and taxa (hyper-costly taxa). These results suggest that impacted sectors should drive efforts to manage the species that are draining financial sources.

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Research Article Thu, 29 Jul 2021 18:55:16 +0300
Economic costs of biological invasions in Ecuador: the importance of the Galapagos Islands https://neobiota.pensoft.net/article/59116/ NeoBiota 67: 375-400

DOI: 10.3897/neobiota.67.59116

Authors: Liliana Ballesteros-Mejia, Elena Angulo, Christophe Diagne, Brian Cooke, Martin A. Nuñez, Franck Courchamp

Abstract: Biological invasions, as a result of human intervention through trade and mobility, are the second biggest cause of biodiversity loss. The impacts of invasive alien species (IAS) on the environment are well known, however, economic impacts are poorly estimated, especially in mega-diverse countries where both economic and ecological consequences of these effects can be catastrophic. Ecuador, one of the smallest mega-diverse countries, lacks a comprehensive description of the economic costs of IAS within its territory. Here, using "InvaCost", a public database that compiles all recorded monetary costs associated with IAS from English and Non-English sources, we investigated the economic costs of biological invasions. We found that between 1983 and 2017, the reported costs associated with biological invasions ranged between US$86.17 million (when considering only the most robust data) and US$626 million (when including all cost data) belonging to 37 species and 27 genera. Furthermore, 99% of the recorded cost entries were from the Galapagos Islands. From only robust data, the costliest identified taxonomic group was feral goats (Capra hircus; US$20 million), followed by Aedes mosquitoes (US$2.14 million) while organisms like plant species from the genus Rubus, a parasitic fly (Philornis downsi), black rats (Rattus rattus) and terrestrial gastropods (Achatina fulica) represented less than US$2 million each. Costs of "mixed-taxa" (i.e. plants and animals) represented the highest (61% of total robust costs; US$52.44 million). The most impacted activity sector was the national park authorities, which spent about US$84 million. Results from robust data also revealed that management expenditures were the major type of costs recorded in the Galapagos Islands; however, costs reported for medical losses related to Aedes mosquitoes causing dengue fever in mainland Ecuador would have ranked first if more detailed information had allowed us to categorize them as robust data. Over 70% of the IAS reported for Ecuador did not have reported costs. These results suggest that costs reported here are a massive underestimate of the actual economic toll of invasions in the country.

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Review Article Thu, 29 Jul 2021 18:55:15 +0300
The economic costs of biological invasions in Brazil: a first assessment https://neobiota.pensoft.net/article/59185/ NeoBiota 67: 349-374

DOI: 10.3897/neobiota.67.59185

Authors: José Ricardo Pires Adelino, Gustavo Heringer, Christophe Diagne, Franck Courchamp, Lucas Del Bianco Faria, Rafael Dudeque Zenni

Abstract: Biological invasions are one of the leading causes of global environmental change and their impacts can affect biodiversity, ecosystem services, human health and the economy. Yet, the understanding on the impacts of invasive alien species is still limited and mostly related to alien species outbreaks and losses in agricultural yield, followed by the understanding of the ecological impacts on natural systems. Notably, the economic impacts of biological invasions have rarely been quantified. Brazil has at least 1214 known alien species from which 460 are recognized as invasive alien species. Still, there are no comprehensive estimates of the cost of their impact and management. Here, we aimed at filling this gap by providing a comprehensive estimate of the economic cost of biological invasions in Brazil. In order to quantify these costs for species, ecosystems and human well-being we used the InvaCost database which is the first global compilation of the economic costs of biological invasions. We found that Brazil reportedly spent a minimum of USD 105.53 billions over 35 years (1984–2019), with an average spent of USD 3.02 (± 9.8) billions per year. Furthermore, USD 104.33 billion were due to damages and losses caused by invaders, whereas only USD 1.19 billion were invested in their management (prevention, control or eradication). We also found that recorded costs were unevenly distributed across ecosystems, and socio-economic sectors, and were rarely evaluated and published. We found that the economic costs with losses and damages were substantially greater than those used for prevention, control or eradication of IAS. Since our data show costs reported in Brazil for only 16 invasive alien species, our estimates are likely a conservative minimum of the actual economic costs of biological invasions in Brazil. Taken together, they indicate that invasive alien species are an important cause of economic losses and that Brazil has mostly opted for paying for the damage incurred by biological invasions rather than investing in preventing them from happening.

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Research Article Thu, 29 Jul 2021 18:55:14 +0300
Economic impact of invasive alien species in Argentina: a first national synthesis https://neobiota.pensoft.net/article/63208/ NeoBiota 67: 329-348

DOI: 10.3897/neobiota.67.63208

Authors: Virginia G. Duboscq-Carra, Romina D. Fernandez, Phillip J. Haubrock, Romina D. Dimarco, Elena Angulo, Liliana Ballesteros-Mejia, Christophe Diagne, Franck Courchamp, Martin A. Nuñez

Abstract: Invasive alien species (IAS) affect natural ecosystems and services fundamental to human well-being, human health and economies. However, the economic costs associated with IAS have been less studied than other impacts. This information can be particularly important for developing countries such as Argentina, where monetary resources for invasion management are scarce and economic costs are more impactful. The present study provides the first analysis of the economic cost of IAS in Argentina at the national level, using the InvaCost database (expanded with new data sources in Spanish), the first global compilation of the reported economic costs of invasions. We analyzed the temporal development of invasions costs, distinguishing costs according to the method reliability (i.e. reproducibility of the estimation methodology) and describing the economic costs of invasions by invaded environment, cost type, activity sector affected and taxonomic group of IAS. The total economic cost of IAS in Argentina between 1995 and 2019 was estimated at US$ 6,908 million. All costs were incurred and 93% were highly reliable. The recorded costs were mainly related to terrestrial environments and the agricultural sector, with lack of costs in other sectors, making it difficult to discuss the actual distribution of invasion costs in Argentina. Nevertheless, the reported costs of IAS in this country are very high and yet likely much underestimated due to important data gaps and biases in the literature. Considering that Argentina has an underdeveloped economy, costs associated with biological invasions should be taken into consideration for preventing invasions, and to achieve a more effective use of available resources.

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Research Article Thu, 29 Jul 2021 18:55:13 +0300
Biological invasions in France: Alarming costs and even more alarming knowledge gaps https://neobiota.pensoft.net/article/59134/ NeoBiota 67: 191-224

DOI: 10.3897/neobiota.67.59134

Authors: David Renault, Eléna Manfrini, Boris Leroy, Christophe Diagne, Liliana Ballesteros-Mejia, Elena Angulo, Franck Courchamp

Abstract: The ever-increasing number of introduced species profoundly threatens global biodiversity. While the ecological and evolutionary consequences of invasive alien species are receiving increasing attention, their economic impacts have largely remained understudied, especially in France. Here, we aimed at providing a general overview of the monetary losses (damages caused by) and expenditures (management of) associated with invasive alien species in France. This country has a long history of alien species presence, partly due to its long-standing global trade activities, highly developed tourism, and presence of overseas territories in different regions of the globe, resulting in a conservative minimum of 2,750 introduced and invasive alien species. By synthesizing for the first time the monetary losses and expenditures incurred by invasive alien species in Metropolitan France and French overseas territories, we obtained 1,583 cost records for 98 invasive alien species. We found that they caused a conservative total amount ranging between US$ 1,280 million and 11,535 million in costs over the period 1993–2018. We extrapolated costs for species invading France, for which costs were reported in other countries but not in France, which yielded an additional cost ranging from US$ 151 to 3,030 millions. Damage costs were nearly eight times higher than management expenditure. Insects, and in particular the Asian tiger mosquito Aedes albopictus and the yellow fever mosquito Ae. aegypti, totalled very high economic costs, followed by non-graminoid terrestrial flowering and aquatic plants (Ambrosia artemisiifolia, Ludwigia sp. and Lagarosiphon major). Over 90% of alien species currently recorded in France had no costs reported in the literature, resulting in high biases in taxonomic, regional and activity sector coverages. To conclude, we report alarming costs and even more alarming knowledge gaps. Our results should raise awareness of the importance of biosecurity and biosurveillance in France, and beyond, as well as the crucial need for better reporting and documentation of cost data.

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Research Article Thu, 29 Jul 2021 18:55:08 +0300
Advanced molecular-based surveillance of quagga and zebra mussels: A review of environmental DNA/RNA (eDNA/eRNA) studies and considerations for future directions https://neobiota.pensoft.net/article/60751/ NeoBiota 66: 117-159

DOI: 10.3897/neobiota.66.60751

Authors: Sheena M. Feist, Richard F. Lance

Abstract: Sensitive methods, capable of rapidly and accurately detecting aquatic invasive species, are in demand. Molecular-based approaches, such as environmental DNA (eDNA) surveys, satisfy these requirements and have grown in popularity. As such, eDNA surveys could aid the effort to combat the colonisation and spread of two notoriously invasive freshwater mussel species, the quagga mussel (Dreissena rostriformis bugensis) and zebra mussel (D. polymorpha), through improved surveillance ability. Here, we provide a review of dreissenid eDNA literature (both grey and published), summarising efforts involved in the development of various assays for use in multiple different technologies (e.g. quantitative PCR, high-throughput sequencing and loop-mediated isothermal amplification) and sampling scenarios. We discuss important discoveries made along the way, including novel revelations involving environmental RNA (eRNA), as well as the advantages and limitations of available methods and instrumentation. In closing, we highlight critical remaining gaps, where further investigation could lead to advancements in dreissenid monitoring capacity.

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Review Article Tue, 13 Jul 2021 10:44:24 +0300
Diversity of alien roadside herbs along an elevational gradient in western Mexico https://neobiota.pensoft.net/article/67192/ NeoBiota 65: 71-91

DOI: 10.3897/neobiota.65.67192

Authors: Isabel Pérez-Postigo, Jörg Bendix, Heike Vibrans, Ramón Cuevas-Guzmán

Abstract: Growing numbers of alien plant species threaten natural ecosystems worldwide. Mexico, as a megadiverse country, has lower numbers of alien species than other regions in America. However, there is a lack of information on the factors that determine the diversity patterns of alien species and their relative importance in the vegetation. The diversity of alien roadside herbs was analysed along an elevational gradient in western Mexico, including their relationship with environmental factors. Three hundred and seventeen herbaceous species were found in 37 sampling sites; 10% were aliens. The proportion of alien species in the ruderal herbaceous communities was lower than the average for this vegetation type in the country. Absolute species richness of natives was significantly and positively correlated with elevation. Absolute species richness of aliens was not significantly correlated with elevation, still; higher values were found at lower elevations. Generalised linear models for relative species richness and relative abundance of aliens with elevation had positive estimates near 0, which, though statistically significant, indicated a weak relationship. Other environmental co-factors, such as the distance to roads and highways, climatic variables, and disturbance indicators, were included in a random forest model. No clear correlation patterns were found. This seemingly random distribution of alien herbaceous plants in the region might be caused by the relatively recent introduction of most of the species. They have not yet had time to expand their distribution to their potential maximum. The early stage of the naturalisation process allows us to minimise the further spread of some species with targeted management and prevent them from becoming invasive.

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Research Article Fri, 28 May 2021 13:54:53 +0300
Assessing the relative importance of human and spatial pressures on non-native plant establishment in urban forests using citizen science https://neobiota.pensoft.net/article/65415/ NeoBiota 65: 1-21

DOI: 10.3897/neobiota.65.65415

Authors: Katherine Duchesneau, Lisa Derickx, Pedro M. Antunes

Abstract: Since 2007, more people in the world live in urban than in rural areas. The development of urban areas has encroached into natural forest ecosystems, consequently increasing the ecological importance of parks and fragmented forest remnants. However, a major concern is that urban activities have rendered urban forests susceptible to non-native species incursions, making them central entry sites where non-native plant species can establish and spread. We have little understanding of what urban factors contribute to this process. Here we use data collected by citizen scientists to determine the differential impacts of spatial and urban factors on non-native plant introductions in urban forests. Using a model city, we mapped 18 urban forests within city limits, and identified all the native and non-native plants present at those sites. We then determined the relative contribution of spatial and socioeconomic variables on the richness and composition of native and non-native plant communities. We found that socioeconomic factors rather than spatial factors (e.g., urban forest area) were important modulators of overall or non-native species richness. Non-native species richness in urban forest fragments was primarily affected by residential layout, recent construction events, and nearby roads. This demonstrates that the proliferation of non-native species is inherent to urban activities and we propose that future studies replicate our approach in different cities to broaden our understanding of the spatial and social factors that modulate invasive species movement starting in urban areas.

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Research Article Mon, 10 May 2021 16:59:19 +0300
Climate change and micro-topography are facilitating the mountain invasion by a non-native perennial plant species https://neobiota.pensoft.net/article/61673/ NeoBiota 65: 23-45

DOI: 10.3897/neobiota.65.61673

Authors: Christian D. Larson, Fredric W. Pollnac, Kaylee Schmitz, Lisa J. Rew

Abstract: Mountainous areas and their endemic plant diversity are threatened by global climate change and invasive species. Mountain plant invasions have historically been minimal, however, climate change and increased anthropogenic activity (e.g. roads and vehicles) are amplifying invasion pressure. We assessed plant performance (stem density and fruit production) of the invasive non-native forb Linaria dalmatica along three mountain roads, over an eight-year period (2008–2015) in the Greater Yellowstone Ecosystem (GYE), USA. We evaluated how L. dalmatica performed in response to elevation, changed over time, responded to climate and how the climate of our sites has changed, and compared elevation, climate, micro-topography (slope aspect and angle), and fruit production among sites with differing temporal trends. Linaria dalmatica stem density and fruit production increased with elevation and demonstrated two temporal groups, those populations where stem densities shrank and those that remained stable or grew over time. Stem density demonstrated a hump-shaped response to summer mean temperature, while fruit production decreased with summer mean maximum temperature and showed a hump-shaped response to winter precipitation. Analysis of both short and long-term climate data from our sites, demonstrated that summer temperatures have been increasing and winters getting wetter. The shrinking population group had a lower mean elevation, hotter summer temperatures, drier winters, had plots that differed in slope aspect and angle from the stable/growing group, and produced less fruit. Regional climate projections predict that the observed climate trends will continue, which will likely benefit L. dalmatica populations at higher elevations. We conclude that L. dalmatica may persist at lower elevations where it poses little invasive threat, and its invasion into the mountains will continue along roadways, expanding into higher elevations of the GYE.

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Research Article Mon, 10 May 2021 09:02:23 +0300
Ornamentals lead the way: global influences on plant invasions in the Caribbean https://neobiota.pensoft.net/article/62939/ NeoBiota 64: 177-197

DOI: 10.3897/neobiota.64.62939

Authors: Julissa Rojas-Sandoval, James D. Ackerman

Abstract: Understanding the historical factors associated with the invasion success of alien species in a region may help us to identify sources, vectors, and pathways that are more likely to originate new invaders. Here, we gather data for traits related to the history of introduction (e.g., continent of origin, reason for introduction, and date of introduction) of 616 alien plant species listed as invasive on 18 island groups across the Caribbean region. We used these data to evaluate how human activity has influenced plant invasions on Caribbean islands over time and whether invasion success could be driven by traits of the introduction process. We found that significantly more invasive plants (54%) were intentionally introduced for ornamental reasons than for any other purpose. Most invaders in the Caribbean are native to Asia, South America, and Africa and the cumulative number of invasive species in this region has been steadily increasing during the last 200 years, but since 1850, this trend has been led by species introduced as ornamentals. We also found a significant association between continent of origin and reason of introduction, with more invaders than expected being ornamentals from Asia and America, and forage species from Africa. Our results show that introduced ornamentals are successfully invading all major habitats across the Caribbean, exacerbating conservation issues and threatening native biodiversity. Armed with knowledge of origins and reasons for introductions, effective biosecurity actions as well as control and management strategies can be better targeted to address the problem of invasive species in the region.

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Research Article Fri, 2 Apr 2021 15:45:50 +0300
Urban host plant utilisation by the invasive Halyomorpha halys (Stål) (Hemiptera, Pentatomidae) in northern Utah https://neobiota.pensoft.net/article/60050/ NeoBiota 64: 87-101

DOI: 10.3897/neobiota.64.60050

Authors: Mark Cody Holthouse, Lori R. Spears, Diane G. Alston

Abstract: The invasive and highly polyphagous brown marmorated stink bug, Halyomorpha halys (Stål), is a severe agricultural and urban nuisance pest in North America. Since its initial invasion into Utah in 2012, H. halys has become well established in urban and suburban locations along the western foothills of the Wasatch Front in northern Utah. Bordering the Great Basin Desert, this area is unique from other North American locations with H. halys due to its high elevation (> 1200 m), aridity (30-year mean RH = 53.1%; dew point = -1.9 °C) and extreme temperatures (the 30-year mean minimum and maximum in January and July in Salt Lake City range from -3.1 to 3.6 °C and 20.3 to 32.4 °C, respectively). To document which plant species harbour H. halys, surveys were conducted in 17 urban/suburban sites in four counties during 2017 and 2018. Halyomorpha halys was more abundant in Salt Lake and Utah counties than in the more northern counties of Davis and Weber and was found on 53 plant species, nine of which hosted two or more developmental stages in both years. The majority of hosts were in the families Fabaceae, Rosaceae and Sapindaceae. Northern catalpa, Catalpa speciosa (Warder), was the most consistent host, supporting a majority of H. halys detections in all life stages; thus we identify it as a sentinel host. Twenty-nine species were novel hosts for H. halys in North America; of these, Acer ginnala Maxim, Populus tremuloides Michx., Prunus armeniaca × domestica ‘Flavor King’ and Prunus virginiana ‘Schubert’ were detected with two or more life stages of H. halys in both years. Peak populations of H. halys occurred from mid-June to mid-September. We describe H. halys plant utilisation by life stage and seasonal period to aid future detection and management of this invasive insect in the greater Intermountain West region.

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Research Article Thu, 28 Jan 2021 20:29:01 +0200
Invasive plant benefits a native plant through plant-soil feedback but remains the superior competitor https://neobiota.pensoft.net/article/57746/ NeoBiota 64: 119-136

DOI: 10.3897/neobiota.64.57746

Authors: Sherri L. Buerdsell, Brook G. Milligan, Erik A. Lehnhoff

Abstract: Plant soil feedback (PSF) occurs when a plant modifies soil biotic properties and those changes in turn influence plant growth, survival or reproduction. These feedback effects are not well understood as mechanisms for invasive plant species. Eragrostis lehmanniana is an invasive species that has extensively colonized the southwest US. To address how PSFs may affect E. lehmanniana invasion and native Bouteloua gracilis growth, soil inoculant from four sites of known invasion age at the Appleton-Whittell Audubon Research Ranch in Sonoita, AZ were used in a PSF greenhouse study, incorporating a replacement series design. The purpose of this research was to evaluate PSF conspecific and heterospecific effects and competition outcomes between the invasive E. lehmanniana and a native forage grass, Bouteloua gracilis. Eragrostis lehmanniana PSFs were beneficial to B. gracilis if developed in previously invaded soil. Plant-soil feedback contributed to competitive suppression of B. gracilis only in the highest ratio of E. lehmanniana to B. gracilis. Plant-soil feedback did not provide an advantage to E. lehmanniana in competitive interactions with B. gracilis at low competition levels but were advantageous to E. lehmanniana at the highest competition ratio, indicating a possible density-dependent effect. Despite being beneficial to B. gracilis under many conditions, E. lehmanniana was the superior competitor.

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Research Article Thu, 28 Jan 2021 13:31:59 +0200
A classification system for predicting invasiveness using climatic niche traits and global distribution models: application to alien plant species in Chile https://neobiota.pensoft.net/article/50049/ NeoBiota 63: 127-146

DOI: 10.3897/neobiota.63.50049

Authors: Ramiro O. Bustamante, Lúa Alves, Estefany Goncalves, Milen Duarte, Ileana Herrera

Abstract: Functional traits that predict plant invasiveness are a central issue in invasion ecology. However, in many cases they are difficult to determine, especially for a large set of species. Climatic niche traits can overcome this problem due to the ease of acquiring them for a large number of species. This effort is critical given that knowledge of species invasiveness is necessary (although not sufficient) to anticipate/manage invasive species. In this study, we examined thermal and hydric niche traits to predict plant invasiveness. We used a set of 49 alien plant species, representative of the alien flora of Chile. Niche traits were obtained using environmental information (WorldClim) and global occurrences. Invasiveness was estimated using global niche models and projection of the potential distribution in Chile. As a final step, we reviewed the literature for a subset of species, documenting their impacts on a) biodiversity, b) crop agriculture and c) livestock. Thermal niche breadth and thermal niche position were the most important niche traits to predict potential distribution (a proxy of invasiveness). Using thermal niche breadth and niche position traits, we constructed a graphical model that classifies alien species as highly invasive (wide thermal niche breadth and low niche position) or low potential to be invasive (narrow niche breadth and high niche position). We also found no association between our invasiveness classification and the documented impact of alien species.

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Research Article Thu, 10 Dec 2020 08:46:26 +0200
Is biocontrol efficacy rather driven by the plant or the antagonist genotypes? A conceptual bioassay approach https://neobiota.pensoft.net/article/54962/ NeoBiota 63: 81-100

DOI: 10.3897/neobiota.63.54962

Authors: Yan Sun, Carine Beuchat, Heinz Müller-Schärer

Abstract: In the new range, invasive species lack their specialist co-evolved natural enemies, which then might be used as biocontrol agents. Populations of both a plant invader in the introduced range and its potential biocontrol agents in the native range may be genetically differentiated among geographically distinct regions. This, in turn, is expected to affect the outcome of their interaction when brought together, and by this the efficacy of the control. It further raises the question, is the outcome of such interactions mainly driven by the genotype of the plant invader (some plant genotypes being more resistant/tolerant to most of the antagonist genotypes), or by the antagonist genotype (some antagonist genotypes being more effective against most of the plant genotypes)? This is important for biocontrol management, as only the latter is expected to result in more effective control, when introducing the right biocontrol agent genotypes. In a third scenario, where the outcome of the interaction is driven by a specific plant by antagonist genotype interactions, an effective control will need the introduction of carefully selected multiple antagonist genotypes. Here, we challenged in a complete factorial design 11 plant genotypes (mainly half-siblings) of the invasive Ambrosia artemisiifolia with larvae of eight genotypes (full-siblings) of the leaf beetle Ophraella communa, a potential biocontrol insect, and assessed larval and adult performance and leaf consumption as proxies of their expected impact on the efficacy of biological control. Both species were collected from several locations from their native (USA) and introduced ranges (Europe and China). In summary, we found O. communa genotype to be the main driver of this interaction, indicating the potential for at least short-term control efficacy when introducing the best beetle genotypes. Besides the importance of investigating the genetic structure both among and within populations of the plant invader and the biocontrol agent during the pre-release phase of a biocontrol program, we advocate integrating such bioassays, as this will give a first indication of the probability for an – at least – short- to mid-term efficacy when introducing a potential biocontrol agent, and on where to find the most efficient agent genotypes.

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Research Article Tue, 8 Dec 2020 15:22:58 +0200
A priority-setting scheme for the management of invasive non-native species in protected areas https://neobiota.pensoft.net/article/52633/ NeoBiota 62: 591-606

DOI: 10.3897/neobiota.62.52633

Authors: Sílvia R. Ziller, Michele de Sá Dechoum, Raphaela Aparecida Duarte Silveira, Hugo Marques da Rosa, Marcelo Souza Motta, Leonardo Filipe da Silva, Beatriz Cunha Mello Oliveira, Rafael D. Zenni

Abstract: Invasion by non-native species is one of the major threats to the conservation of biodiversity and to the provision of ecosystem services by protected areas. Invasive species often co-occur in protected areas, represented by sparse, isolated individuals or populations in different stages in the process of invasion. Species invasiveness, habitat invasibility and impact also differ between ecosystems, so the risk of invasion varies. Besides, prioritization is required due to constraints on time, financial and other resources. Priority-setting is therefore key to help protected area managers invest efforts on biological invasions that offer the best chances of producing large-scale positive results at the lowest cost possible. A priority-setting scheme for the control of invasive non-native species in natural areas is presented in this paper. The scheme, based on field observations of species occurrences, was applied to the Itatiaia National Park (Brazil). Priorities are calculated from a combination of three criteria attributed to each occurrence: species risk of invasion considering local ecosystems, invasion stage, and species frequency. Data collected in the field in the Itatiaia National Park were used to calculate priorities for 50 non-native species (six animals and 44 plants) in four locations in the Park. The highest priorities were attributed to species of high risk in an early stage of invasion occurring in one site, whereas a few widespread species of low risk were given lower priority. The scheme has proven functional for setting priorities for the control of non-native species in the Itatiaia National Park and in many other protected areas in Brazil.

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Research Article Thu, 15 Oct 2020 20:20:25 +0300
Eat and be eaten: trophic interactions of the introduced frog Scinax quinquefasciatus in anthropogenic environments in Galápagos https://neobiota.pensoft.net/article/53256/ NeoBiota 61: 17-31

DOI: 10.3897/neobiota.61.53256

Authors: M. Mar Moretta-Urdiales, Raffael Ernst, José Pontón-Cevallos, Rafael Bermúdez, Heinke Jäger

Abstract: While the Galápagos Archipelago is known for its endemic flora and fauna, many introduced species have also become naturalised there, especially on the human-inhabited islands. The only amphibian species known to have established on the islands, the Fowler’s snouted treefrog (Scinax quinquefasciatus), is thought to have arrived about two decades ago. Since then, this treefrog has substantially extended its range to the islands of Santa Cruz and Isabela. Our study explores the potential influence of this introduced amphibian on native trophic systems on Santa Cruz and identifies potential antagonists likely to control larval frog populations. To understand the impact of S. quinquefasciatus as a predator of local invertebrate fauna, we performed a stomach-content analysis of 228 preserved adult specimens from seven different localities on Santa Cruz. Of the 11 macroinvertebrate orders recorded, Lepidoptera constituted more than 60% of the contents. We also identified active predators of S. quinquefasciatus tadpoles: larvae of the endemic diving beetle (Thermonectus basillarus galapagoensis). To determine the efficiency of this predator, we conducted predator-prey experiments in ex situ conditions. Tadpole predation was highest after first exposure to the predator and significantly decreased over time. Our experimental results demonstrate that although T. b. galapagoensis larvae are effective tadpole predators, their feeding saturation rates are likely inadequate for frog population control. Our findings provide the first baseline data necessary to make informed ecological impact assessments and monitoring schemes on Santa Cruz for this introduced treefrog.

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Research Article Thu, 8 Oct 2020 08:31:41 +0300
Estimating the benefit of quarantine: eradicating invasive cane toads from islands https://neobiota.pensoft.net/article/34941/ NeoBiota 60: 117-136

DOI: 10.3897/neobiota.60.34941

Authors: Adam S. Smart, Reid Tingley, Ben L. Phillips

Abstract: Islands are increasingly used to protect endangered populations from the negative impacts of invasive species. Quarantine efforts on islands are likely to be undervalued in circumstances in which a failure incurs non-economic costs. One approach to ascribe monetary value to such efforts is by modeling the expense of restoring a system to its former state. Using field-based removal experiments on two different islands off northern Australia separated by > 400 km, we estimate cane toad densities, detection probabilities, and the resulting effort needed to eradicate toads from an island. We use these estimates to conservatively evaluate the financial benefit of cane toad quarantine across offshore islands prioritized for conservation management by the Australian federal government. We calculate density as animals per km of freshwater shoreline, and find striking concordance of density estimates across our two island study sites: a mean density of 352 [289, 466] adult toads per kilometre on one island, and a density of 341 [298, 390] on the second. Detection probability differed between our two study islands (Horan Island: 0.1 [0.07, 0.13]; Indian Island: 0.27 [0.22, 0.33]). Using a removal model and the financial costs incurred during toad removal, we estimate that eradicating cane toads would, on average, cost between $22 487 [$14 691, $34 480] (based on Horan Island) and $39 724 [$22 069, $64 001] AUD (Indian Island) per km of available freshwater shoreline. We estimate the remaining value of toad quarantine across islands that have been prioritized for conservation benefit within the toads’ predicted range, and find the net value of quarantine efforts to be $43.4 [28.4–66.6] – $76.7 [42.6–123.6] M depending on which island dataset is used to calibrate the model. We conservatively estimate the potential value of a mainland cane toad containment strategy – to prevent the spread of toads into the Pilbara Bioregion – to be $80 [52.6–123.4] – $142 [79.0–229.0] M. We present a modeling framework that can be used to estimate the value of preventative management, via estimating the length and cost of an eradication program. Our analyses suggest that there is substantial economic value in cane toad quarantine efforts across Australian offshore islands and in a proposed mainland containment strategy.

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Research Article Thu, 1 Oct 2020 12:17:48 +0300
A bobber’s perspective on angler-driven vectors of invasive species transmission https://neobiota.pensoft.net/article/54579/ NeoBiota 60: 97-115

DOI: 10.3897/neobiota.60.54579

Authors: Rachel M. Fricke, Spencer A. Wood, Dustin R. Martin, Julian D. Olden

Abstract: Prevention of aquatic invasive species is a fundamental management challenge. With hundreds of millions of people participating in fishing trips each year, understanding angler movements that transmit invasive species can provide critical insight into the most effective locations and scales at which to apply preventative measures. Recent evidence suggests that mobile technologies provide new opportunities to understand different types of angler movement behaviour beyond what is possible with infrequently and sparsely conducted in-person boat surveys and mail questionnaires. Here we capitalise on data provided by ReelSonar’s iBobber, a sonar-enabled bobber with over 5 M recorded fishing locations, globally. By quantifying geographic patterns of fishing activities and assessing how these patterns change seasonally, we explore angler behaviour across the entire continental United States in terms of fishing frequency and distance travelled between sites and characterise the attributes of fished ecosystems. We found that iBobber users (anglers) undertook 66,918 trips to 20,049 different water-bodies over a two-year period. Anglers who use iBobber were more likely to visit larger, deeper and more urbanised water-bodies and these water-bodies were over five times more likely to be a reservoir compared to a lake. Inter-water-body travel road distances averaged 93 km (SD = 277 km; range < 1–300 km) and nearly half of these movements occurred over a timespan of two days or less, a timeframe that we show falls well within the desiccation tolerance window of many prevalent plant and animal invasive species. Our study offers novel insight into spatiotemporal patterns of angler behaviour well beyond the geographical and temporal extent of conventional ground-collected approaches and carries important implications for predicting and preventing future transmission of aquatic invasive species via recreational fishing.

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Research Article Wed, 2 Sep 2020 08:29:00 +0300
Please don’t mow the Japanese knotweed! https://neobiota.pensoft.net/article/56935/ NeoBiota 60: 19-23

DOI: 10.3897/neobiota.60.56935

Authors: Daniel Jones, Mike S. Fowler, Sophie Hocking, Daniel Eastwood

Abstract: Letter To The Editor

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Letter To The Editor Wed, 12 Aug 2020 13:12:02 +0300
Multi-taxa inventory of naturalized species in Chile https://neobiota.pensoft.net/article/55366/ NeoBiota 60: 25-41

DOI: 10.3897/neobiota.60.55366

Authors: Nicol Fuentes, Alicia Marticorena, Alfredo Saldaña, Viviane Jerez, Juan Carlos Ortiz, Pedro Victoriano, Rodrigo A. Moreno, Juan Larraín, Cristobal Villaseñor-Parada, Götz Palfner, Paulina Sánchez, Aníbal Pauchard

Abstract: Here we present a multi-taxa inventory of naturalized alien species recorded on continental Chile and adjacent marine habitats, including eight taxonomic groups. We identified 1,122 species. These comprise 790 vascular plants (terrestrial and aquatic); 31 nonvascular plants [Bryophyta (mosses), Marchantiophyta (liverworts) and Anthocerotophyta (hornworts)]; 18 marine and freshwater macro and micro algae; 71 fungi; 39 terrestrial vertebrates (amphibians, reptiles, mammals and birds); 108 insects; 37 marine and freshwater invertebrates and vertebrates (6 polychaetes, 3 mollusks and 28 Pisces); and 28 terrestrial gastropods. For all taxonomic groups, naturalized species were found to mainly be distributed in regions with Mediterranean and temperate climates, with few at either extreme of the country. The invasion curves show that naturalized species first underwent a positive increment, followed by an apparent plateau phase, mainly in vascular plants, insects and vertebrates. In fungi, marine and freshwater macro and microalgae, vertebrates and invertebrates, the cumulative number of naturalized species increased sharply starting in the early 20th century; the lack of collections before 1900 is also evident. When considering naturalized species as a whole, this inventory highlights that the rate of new naturalizations consistently increased after 1950, especially for some taxonomic groups such as insects, fungi, and vascular plants. This multi-taxa inventory of naturalized species provides a platform for national reporting on biodiversity indicators and highlights areas where Chile must invest resources to manage biological invasions.

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Research Article Wed, 12 Aug 2020 09:51:21 +0300
CONTAIN: Optimising the long-term management of invasive alien species using adaptive management https://neobiota.pensoft.net/article/52022/ NeoBiota 59: 119-138

DOI: 10.3897/neobiota.59.52022

Authors: Xavier Lambin, David Burslem, Paul Caplat, Thomas Cornulier, Gabriella Damasceno, Laura Fasola, Alessandra Fidelis, Pablo García-Díaz, Bárbara Langdon, Eirini Linardaki, Lia Montti, Jaime Moyano, Martín A. Nuñez, Stephen C.F. Palmer, Aníbal Pauchard, Euan Phimister, José Cristóbal Pizarro, Priscila Powell, Eduardo Raffo, Ignacio A. Rodriguez-Jorquera, Ignacio Roesler, Jorge A. Tomasevic, Justin M.J. Travis, Claudio Verdugo

Abstract: Invasive Alien Species (IAS) threaten biodiversity, ecosystem functions and services, modify landscapes and impose costs to national economies. Management efforts are underway globally to reduce these impacts, but little attention has been paid to optimising the use of the scarce available resources when IAS are impossible to eradicate, and therefore population reduction and containment of their advance are the only feasible solutions. CONTAIN, a three-year multinational project involving partners from Argentina, Brazil, Chile and the UK, started in 2019. It develops and tests, via case study examples, a decision-making toolbox for managing different problematic IAS over large spatial extents. Given that vast areas are invaded, spatial prioritisation of management is necessary, often based on sparse data. In turn, these characteristics imply the need to make the best decisions possible under likely heavy uncertainty. Our decision-support toolbox will integrate the following components: (i) the relevant environmental, social, cultural, and economic impacts, including their spatial distribution; (ii) the spatio-temporal dynamics of the target IAS (focusing on dispersal and population recovery); (iii) the relationship between the abundance of the IAS and its impacts; (iv) economic methods to estimate both benefits and costs to inform the spatial prioritisation of cost-effective interventions. To ensure that our approach is relevant for different contexts in Latin America, we are working with model species having contrasting modes of dispersal, which have large environmental and/or economic impacts, and for which data already exist (invasive pines, privet, wasps, and American mink). We will also model plausible scenarios for data-poor pine and grass species, which impact local people in Argentina, Brazil and Chile. We seek the most effective strategic management actions supported by empirical data on the species’ population dynamics and dispersal that underpin reinvasion, and on intervention costs in a spatial context. Our toolbox serves to identify key uncertainties driving the systems, and especially to highlight gaps where new data would most effectively reduce uncertainty on the best course of action. The problems we are tackling are complex, and we are embedding them in a process of co-operative adaptive management, so that both researchers and managers continually improve their effectiveness by confronting different models to data. Our project is also building research capacity in Latin America by sharing knowledge/information between countries and disciplines (i.e., biological, social and economic), by training early-career researchers through research visits, through our continuous collaboration with other researchers and by training and engaging stakeholders via workshops. Finally, all these activities will establish an international network of researchers, managers and decision-makers. We expect that our lessons learned will be of use in other regions of the world where complex and inherently context-specific realities shape how societies deal with IAS.

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Project Description Wed, 5 Aug 2020 08:24:17 +0300
Effects of a recalcitrant understory fern layer in an enclosed tropical restoration experiment https://neobiota.pensoft.net/article/51906/ NeoBiota 59: 99-118

DOI: 10.3897/neobiota.59.51906

Authors: Luis C. Beltrán, Karla María Aguilar-Dorantes, Henry F. Howe

Abstract: Establishing mixed-species tree plantings and fencing them to protect seedlings from herbivory is a valuable strategy for reconnecting forest fragments separated by agropastoral lands. However, fencing may provide exotic plants with the escape from herbivory required to invade the understory of planted communities. Here we take advantage of such a situation to ask how the identity of planted species and the resulting canopy cover influenced invasion success by the Asian swordtail fern (Nephrolepis brownii Desv. Nephrolepidaceae) in a 13-year-old tropical restoration experiment. Through a seed addition experiment, we also evaluated the effects the ferns had on recruiting seedlings. We found that the invasion was most acute in the unplanted control plots where canopy cover was consistently scarce. Frond density correlated negatively with canopy cover, though most of the variance in the model is explained by the design of our experiment (r2m = .161, r2c = .460). Between planting treatments that differed in the dispersal mode of the planted trees, the wind-dispersed treatment had higher fern density and longer fronds than the animal-dispersed treatment. The animal-dispersed treatment had the highest recruiting species richness, which was negatively correlated with fern density (r2 = .748). The seed addition experiment confirmed that mortality rates increased where frond density was higher (F1,41 = 7.159, p = .011) and germination rates were lowered for the smaller-seeded species (F1,42 = 13.2, p = .002). To prevent recalcitrant understory layers from establishing in plantings in the future, we recommend: (1) establishing larger plantings or expanding existing ones to minimize edge effects (particularly light filtration), (2) supplementing young plantings with additional seedlings to prevent canopy gaps from forming, and (3) planting an assemblage of species that cover the full forest strata and have consistently full tree-canopies.

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Research Article Thu, 30 Jul 2020 16:16:59 +0300
Predicting the invasion range for a highly polyphagous and widespread forest herbivore https://neobiota.pensoft.net/article/53550/ NeoBiota 59: 1-20

DOI: 10.3897/neobiota.59.53550

Authors: Laura M. Blackburn, Joseph S. Elkinton, Nathan P. Havill, Hannah J. Broadley, Jeremy C. Andersen, Andrew M. Liebhold

Abstract: Here we compare the environmental niche of a highly polyphagous forest Lepidoptera species, the winter moth (Operophtera brumata), in its native and invaded range. During the last 90 years, this European tree folivore has invaded North America in at least three regions and exhibited eruptive population behavior in both its native and invaded range. Despite its importance as both a forest and agricultural pest, neither the potential extent of this species’ invaded range nor the geographic source of invading populations from its native range are known. Here we fit a climatic niche model, based on the MaxEnt algorithm, to historical records of winter moth occurrence in its native range and compare predictions of suitable distributions to records from the invaded range. We modeled this distribution using three spatial bins to overcome sampling bias for data obtained from public databases and averaged the multi-continental suitable habitat prediction. Results indicate that this species is distributed across a wide range of climates in its native range but occupies a narrower range in its invaded habitat. Furthermore, the lack of a close fit between climatic conditions in parts of its invaded range and its known native range suggests the possibility that this species has adapted to new climatic conditions during the invasion process. These models can be used to predict suitable habitats for winter moth invasions worldwide and to gain insight into possible origins of North American populations.

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Research Article Tue, 28 Jul 2020 08:57:12 +0300
Spatiotemporal patterns of non-native terrestrial gastropods in the contiguous United States https://neobiota.pensoft.net/article/52195/ NeoBiota 57: 133-152

DOI: 10.3897/neobiota.57.52195

Authors: Nicholas S. Gladstone, Trystan A. Bordeau, Christy Leppanen, Michael L. McKinney

Abstract: The contiguous United States (CONUS) harbor a significant non-native species diversity. However, spatiotemporal trends of some groups such as terrestrial gastropods (i.e., land snails and slugs) have not been comprehensively considered, and therefore management has been hindered. Here, our aims were to 1.) compile a dataset of all non-native terrestrial gastropod species with CONUS occurrence records, 2.) assess overarching spatiotemporal patterns associated with these records, 3.) describe the continental origin of each species, and 4.) compare climatic associations of each species in their indigenous and introduced CONUS ranges. We compiled a georeferenced dataset of 10,097 records for 22 families, 48 genera, and 69 species, with > 70% of records sourced from the citizen science database iNaturalist. The species Cornu aspersum Müller, 1774 was most prevalent with 3,672 records. The majority (> 92%) of records exhibit an indigenous Western European and Mediterranean distribution, with overlap in broad-scale climatic associations between indigenous and CONUS ranges. Records are most dense in urban metropolitan areas, with the highest proportion of records and species richness in the state of California. We show increased prevalence of non-native species through time, largely associated with urbanized areas with high human population density. Moreover, we show strong evidence for a role for analogous climates in dictating geographic fate and pervasiveness between indigenous and CONUS ranges for non-native species.

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Research Article Wed, 17 Jun 2020 13:58:47 +0300
Do dense layers of invasive plants elevate the foraging intensity of small mammals in temperate deciduous forests? A case study from Pennsylvania, USA https://neobiota.pensoft.net/article/49581/ NeoBiota 56: 73-88

DOI: 10.3897/neobiota.56.49581

Authors: Ryan M. Utz, Alysha Slater, Hannah R. Rosche, Walter P. Carson

Abstract: Monospecific stands of invasive plants can dramatically restructure habitat for fauna, thereby elevating population densities or promoting foraging of consumer species who benefit in the altered habitat. For example, dense stands of invasive plants may protect small mammals from predators, which in turn could increase foraging pressure on seeds that small mammals feed upon. We used a before-after, control-impact experimental design to test whether small mammal capture rates were higher and giving-up densities (GUDs) lower beneath dense stands of Berberis thunbergii, an invasive shrub with a rapidly expanding range throughout eastern North America. Our experimental design included three plot categories: 1) plots heavily invaded by B. thunbergii, 2) control plots lacking invasive shrub cover, and 3) invaded plots where we eradicated B. thunbergii midway through the study. Although our overall small mammal capture rate was low, small mammal captures were 65% higher in B. thunbergii invaded habitat relative to control plots and eradication lowered capture rates by 77%. GUDs were also 26% higher within B. thunbergii relative to control plots and eradication decreased GUDs by 65%. Our findings suggest that small mammals perceive dense stands of B. thunbergii as relatively safe foraging habitat. Prior surveys within our study locations revealed dramatically depressed tree seedling densities under B. thunbergii, thus invasive plants may promote intensive foraging by small mammals and reduce recruitment for species with foraged seeds or seedlings.

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Short Communication Thu, 14 May 2020 16:38:29 +0300
The impact is in the details: evaluating a standardized protocol and scale for determining non-native insect impact https://neobiota.pensoft.net/article/38981/ NeoBiota 55: 61-83

DOI: 10.3897/neobiota.55.38981

Authors: Ashley N. Schulz, Angela M. Mech, Craig R. Allen, Matthew P. Ayres, Kamal J. K. Gandhi, Jessica Gurevitch, Nathan P. Havill, Daniel A. Herms, Ruth A. Hufbauer, Andrew M. Liebhold, Kenneth F. Raffa, Michael J. Raupp, Kathryn A. Thomas, Patrick C. Tobin, Travis D. Marsico

Abstract: Assessing the ecological and economic impacts of non-native species is crucial to providing managers and policymakers with the information necessary to respond effectively. Most non-native species have minimal impacts on the environment in which they are introduced, but a small fraction are highly deleterious. The definition of ‘damaging’ or ‘high-impact’ varies based on the factors determined to be valuable by an individual or group, but interpretations of whether non-native species meet particular definitions can be influenced by the interpreter’s bias or level of expertise, or lack of group consensus. Uncertainty or disagreement about an impact classification may delay or otherwise adversely affect policymaking on management strategies. One way to prevent these issues would be to have a detailed, nine-point impact scale that would leave little room for interpretation and then divide the scale into agreed upon categories, such as low, medium, and high impact. Following a previously conducted, exhaustive search regarding non-native, conifer-specialist insects, the authors independently read the same sources and scored the impact of 41 conifer-specialist insects to determine if any variation among assessors existed when using a detailed impact scale. Each of the authors, who were selected to participate in the working group associated with this study because of their diverse backgrounds, also provided their level of expertise and uncertainty for each insect evaluated. We observed 85% congruence in impact rating among assessors, with 27% of the insects having perfect inter-rater agreement. Variance in assessment peaked in insects with a moderate impact level, perhaps due to ambiguous information or prior assessor perceptions of these specific insect species. The authors also participated in a joint fact-finding discussion of two insects with the most divergent impact scores to isolate potential sources of variation in assessor impact scores. We identified four themes that could be experienced by impact assessors: ambiguous information, discounted details, observed versus potential impact, and prior knowledge. To improve consistency in impact decision-making, we encourage groups to establish a detailed scale that would allow all observed and published impacts to fall under a particular score, provide clear, reproducible guidelines and training, and use consensus-building techniques when necessary.

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Research Article Fri, 3 Apr 2020 11:24:52 +0300
Context-dependent differences in the functional responses of conspecific native and non-native crayfishes https://neobiota.pensoft.net/article/38668/ NeoBiota 54: 71-88

DOI: 10.3897/neobiota.54.38668

Authors: Jaime Grimm, Jaimie T.A. Dick, Hugo Verreycken, Jonathan M. Jeschke, Stefan Linzmaier, Anthony Ricciardi

Abstract: Invasive species are proliferating globally and cause a range of impacts, necessitating risk assessment and prioritization prior to management action. Experimentally derived estimates of per capita effects (e.g. functional responses) have been advocated as predictors of field impacts of potential invaders. However, risk assessments based on estimates from single populations can be misleading if per capita effects vary greatly across space and time. Here, we present a large-scale, multi-population comparison of per capita effects of the American spinycheek crayfish, Faxonius (formerly Orconectes) limosus—a species with an extensive invasion history in eastern North America and Europe. Functional responses were measured on individuals from six geographically disparate populations of F. limosus in its native and invaded ranges on two continents. These revealed inter-population differences in both the maximum feeding rate and functional response type that could not be explained by the biogeographic origin of the population nor by time since the invasion. We propose that other differences in source communities (including the presence of competitors) impose selective pressures for phenotypic traits that result in dissimilar per capita effects. We also compared functional responses of the congeners F. limosus and F. virilis in the presence and absence of potential competitors to examine indirect competitive effects on feeding behaviour. The maximum feeding rate of F. limosus, but not F. virilis, was suppressed in the presence of heterospecific and conspecific competitors, demonstrating how the per capita effects of these species can differ across biotic contexts. In the competitor-presence experiments, individuals from the invasive population of F. limosus consistently had a higher maximum feeding rate than those of the native F. virilis, regardless of treatment. Our results caution against invasion risk assessments that use information from only one (or a few) populations or that do not consider the biotic context of target habitats. We conclude that comparative functional responses offer a rapid assessment tool for invader ecological impacts under context dependencies when multiple populations are analyzed.

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Research Article Wed, 12 Feb 2020 09:02:05 +0200
Effects of osmotic and thermal shock on the invasive aquatic mudsnail Potamopyrgus antipodarum: mortality and physiology under stressful conditions https://neobiota.pensoft.net/article/39465/ NeoBiota 54: 1-22

DOI: 10.3897/neobiota.54.39465

Authors: Esteban M. Paolucci, Erik V. Thuesen

Abstract: Invasive freshwater species, such as the exotic mollusc Potamopyrgus antipodarum (New Zealand mudsnail), can frequently survive under harsh conditions, including brackish and hypoxic environments. We experimentally assessed the effects of osmotic (0, 10, 20, 25 and 30 psu) and thermal (20 °C) shock on mortality, activity and physiology of P. antipodarum collected at Capitol Lake, Olympia, Washington, USA, during winter and spring seasons when environmental temperature was 5 and 10 °C respectively. We measured standard metabolic rate and enzymatic activities (malate dehydrogenase, lactate dehydrogenase, alanopine dehydrogenase) in snails after a 10-day acclimation period at high salinity. Significantly higher mortalities were observed at higher salinities; the strongest effects occurred on snails collected at the end of winter, and exposed to 30 psu and 20 °C (100% mortality in 3 days). When snails were collected during the spring, 100% mortality was observed after 40 days at 30 psu and 20 °C. Standard metabolic rates were significantly lower when snails were exposed to salinities of 25 and 30 psu, even after 10 days of acclimation. Enzymatic activities showed small but significant declines after 10 days at 30 psu reflecting the declines observed in overall metabolism. The physiological tolerances to temperature and salinity displayed by this population of P. antipodarum make its eradication from Capital Lake difficult to achieve.

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Research Article Thu, 9 Jan 2020 08:41:57 +0200
InvasiBES: Understanding and managing the impacts of Invasive alien species on Biodiversity and Ecosystem Services https://neobiota.pensoft.net/article/35466/ NeoBiota 50: 109-122

DOI: 10.3897/neobiota.50.35466

Authors: Belinda Gallardo, Sven Bacher, Bethany Bradley, Francisco A. Comín, Laure Gallien, Jonathan M. Jeschke, Cascade J. B. Sorte, Montserrat Vilà

Abstract: Invasive Alien Species (IAS) are amongst the most significant drivers of species extinction and ecosystem degradation, causing negative impacts on ecosystem services and human well-being. InvasiBES, a project funded by BiodivERsA-Belmont Forum for 2019–2021, will use data and models across scales, habitats and species to understand and anticipate the multi-faceted impacts of IAS and to provide tools for their management. Using Alien Species Narratives as reference, we will design future intervention scenarios focused on prevention, control and eradication of IAS in Europe and the United States, through a participatory process bringing together the expertise of scientists and stakeholders. We will also adapt current impact assessment protocols to assess both the detrimental and beneficial impacts of IAS on biodiversity and ecosystem services. This information will then be combined with maps of the potential distribution of Invasive Species of Interest in Europe under current and future climate-change scenarios. Likewise, we will anticipate areas under risk of invasion by range-shifting plants of concern in the US. Finally, focusing on three local-scale studies that cover a range of habitats (freshwater, terrestrial and marine), invasive species (plants and animals) and ecosystem services (supporting, provisioning, regulating and cultural), we will use empirical field data to quantify the real-world impacts of IAS on biodiversity and ecosystem services and calculate indicators of ecosystem recovery after the invader is removed. Spatial planning tools (InVEST) will be used to evaluate the costs and benefits of species-specific intervention scenarios at the regional scale. Data, models and maps, developed throughout the project, will serve to build scenarios and models of biodiversity and ecosystem services that are relevant to underpin management of IAS at multiple scales.

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Project Description Mon, 14 Oct 2019 13:37:32 +0300
First indication of Japanese mitten crabs in Europe and cryptic genetic diversity of invasive Chinese mitten crabs https://neobiota.pensoft.net/article/34881/ NeoBiota 50: 1-29

DOI: 10.3897/neobiota.50.34881

Authors: Sarah Hayer, Dirk Brandis, Günther B. Hartl, Christine Ewers-Saucedo

Abstract: The Chinese mitten crab (Eriocheir sinensis) is a prominent aquatic invader with substantial negative economic and environmental impacts. The aim of the present study was to re-evaluate the genetic diversity of mitten crabs throughout their native and invaded ranges based on publicly available sequence data, and assess if multiple introductions or rapid adaptation could be responsible for biologically divergent mitten crabs in Northern Europe. We assembled available genetic data of a fragment of the mitochondrial cytochrome c oxidase subunit one gene (COI) for all species of the genus Eriocheir. We applied phylogenetic and population genetic analyses to compare native and invasive populations, and to identify possible source populations. The phylogenetic reconstruction revealed that five COI sequences from Europe, morphologically identified as Chinese mitten crab, actually belong to the Japanese mitten crab (Eriocheir japonica), representing the first indication of its presence in European waters. All other COI sequences from Europe could unambiguously be assigned to the Chinese mitten crab. In some Northern German populations of Chinese mitten crabs, genetic diversity was surprisingly high, due to seven unique haplotypes encoding several amino acid substitutions. This diversity may reflect a cryptic introduction from an unsampled native location, or rapid adaptation in the invaded range. Based on the genetic diversity shared between native and introduced range, Feiyunjiang, a tributary of the Yangtze River, emerges as a plausible source population for the original introduction of Chinese mitten crabs to Europe. This study highlights the complex and dynamic invasion processes of mitten crabs in Europe. We urge to further monitor mitten crab invasions using genetic tools.

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Research Article Wed, 28 Aug 2019 13:40:15 +0300
Scientific literature on invasive alien species in a megadiverse country: advances and challenges in Mexico https://neobiota.pensoft.net/article/36201/ NeoBiota 48: 113-127

DOI: 10.3897/neobiota.48.36201

Authors: Jorge E. Ramírez-Albores, Ernesto I. Badano, Joel Flores, José Luis Flores-Flores, Laura Yáñez-Espinosa

Abstract: Interest in invasive species has increased around the world over the last several decades. In Mexico, studies on invasive species date as early as 1939 and the number of publications has increased considerably in recent decades. However, to our knowledge, the analysis of information gaps and research priorities is lacking. Therefore, it is necessary to identify gaps in the knowledge of invasive species in order to define future research priorities and focus conservation efforts. We assessed the current state of knowledge of biological invasions in Mexico based on the existing literature. Our aim was to identify in which areas information is absent or insufficient and which areas should be prioritised. We identified a total of 869 references. The number of references increased over time and the topics were strongly biased towards two areas: 1) natural history and geographical distribution patterns and 2) effects on native biota and ecosystems. The remaining topics were only moderately or poorly studied. Most studies focused on vascular plants (n = 280) and fishes (n = 174). Notably, a large portion of the references (n = 215) focused on only eight invasive alien species, including their ecological and socioeconomic impacts. Only 95 references examined the effects of alien species on biodiversity; these studies were mainly carried out on islands (n = 41) or in terrestrial or freshwater ecosystems in protected natural areas (n = 165). The findings of the present review can guide future studies in filling in the existing research gaps on biological invasions. Additionally, future studies should aim to define national priorities of the impacts of biological invasions and to promote the prevention and control of alien species by considering the distinct vectors and pathways of introduction and movement.

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Research Article Tue, 16 Jul 2019 11:38:39 +0300
Population responses of common carp Cyprinus carpio to floods and droughts in the Pampean wetlands of South America https://neobiota.pensoft.net/article/34850/ NeoBiota 48: 25-44

DOI: 10.3897/neobiota.48.34850

Authors: Tomás Maiztegui, Claudio R.M. Baigún, Javier R. Garcia de Souza, Olaf L.F. Weyl, Darío Colautti

Abstract: Common carp (Cyprinus carpio) is a global invader that exhibits a wide distribution in Argentina, particularly in shallow lakes and wetlands of the Pampean region. The hydrological conditions of these environments are driven by variations in annual precipitation that determine inter annual changes in water levels leading to flood-drought cycles. The present study focused on understanding the C. carpio population responses to annual rainfall regime and long-term flood and drought events in the Ajó wetlands located in the east of the Pampean region. The results of a two-year biological sampling program showed that C. carpio feeding rate, reproduction, condition, and recruitment were associated with the hydrological cycle. Otolith derived age structure of the population and back-calculated recruitment strength revealed that extraordinary flooding events generated strong cohorts while dry years resulted in low recruitment. Its long-life span (maximum 14 years in Ajó) coupled with a high fecundity, and broad diet allows C. carpio to persist in refugia during dry years and capitalize on wet years when inundation of the floodplain enhances recruitment and facilitates spread. Management and control strategies for this invader should therefore incorporate hydrological variability by promoting intensive removal campaigns during dry years when populations are dominated by large fish confined in remnant water-bodies and, during wet years, carp harvest fisheries should be promoted to reduce population density when increased connectivity is likely to facilitate spread.

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Research Article Tue, 2 Jul 2019 10:06:53 +0300
Comparative feeding behaviour of native and introduced terrestrial snails tracks their ecological impacts https://neobiota.pensoft.net/article/35000/ NeoBiota 47: 81-94

DOI: 10.3897/neobiota.47.35000

Authors: Tedi Hoxha, Steve Crookes, Ian MacIsaac, Xuexiu Chang, Mattias Johansson, Jaimie T.A. Dick, Annegret Nicolai, Hugh J. MacIsaac

Abstract: A developing body of theory and empirical evidence suggest that feeding behaviour as measured by the functional response (FR) can assist researchers in assessing the relative potential, ecological impacts and competitive abilities of native and introduced species. Here, we explored the FRs of two land snails that occur in south-western Ontario, one native (Mesodon thyroidus) and one non-indigenous (Cepaea nemoralis) to Canada. The non-indigenous species appears to have low ecological impact and inferior competitive abilities. Consistent with theory, while both species conformed to Type II functional responses, the native species had a significantly higher attack rate (5.30 vs 0.41, respectively) and slightly lower handling time (0.020 vs 0.023), and hence a higher maximum feeding rate (50.0 vs 43.5). The non-indigenous species exhibited a significantly longer time to contact for a variety of food types, and appeared less discriminating of paper that was offered as a non-food type. The non-indigenous species also ate significantly less food when in mixed species trials with the native snail. These feeding patterns match the known low ecological impact of the introduced snail and are consistent with the view that it is an inferior competitor relative to the native species. However, field experimentation is required to clarify whether the largely microallopatric distributions of the two species in south-western Ontario reflect competitive dominance by the native species or other factors such as habitat preference, feeding preferences or predator avoidance. The relative patterns of feeding behaviour and ecological impact are, however, fully in line with recent functional response theory and application.

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Research Article Thu, 20 Jun 2019 16:46:46 +0300
Unravelling the origin and introduction pattern of the tropical species Paracaprella pusilla Mayer, 1890 (Crustacea, Amphipoda, Caprellidae) in temperate European waters: first molecular insights from a spatial and temporal perspective https://neobiota.pensoft.net/article/32408/ NeoBiota 47: 43-80

DOI: 10.3897/neobiota.47.32408

Authors: M. Pilar Cabezas, Macarena Ros, António Múrias dos Santos, Gemma Martínez-Laiz, Raquel Xavier, Lou Montelli, Razy Hoffman, Abir Fersi, Jean Claude Dauvin, José Manuel Guerra-García

Abstract: Paracaprella pusilla Mayer, 1890 is a tropical caprellid species recently introduced to the Eastern Atlantic coast of the Iberian Peninsula and the Mediterranean Sea. In this study, we used direct sequencing of mitochondrial (COI and 16S) and nuclear (28S and ITS) genes to compare genetic differences in presumed native and introduced populations in order to infer its introduction pattern and to shed light on the native range of this species. The temporal pattern of genetic diversity at the westernmost limit of the geographic range of P. pusilla in Europe (the Atlantic coast of southern Spain) over an eight-year period was also investigated. Our results confirm P. pusilla as a neocosmopolitan species and suggest that the species is native to the Atlantic coast of Central and South America. Paracaprella pusilla seems to have been introduced into European waters from multiple introduction pathways and source populations, which are likely to include populations from coastal waters of Brazil. Multiple introduction pathways may have been involved, with the most important being commercial shipping through the Strait of Gibraltar. While this tropical species appears to be expanding in the Mediterranean, populations from the westernmost limit of its geographic range in Europe showed a temporal instability. This study constitutes the first molecular approach focused on this species, but it is also the first study of temporal change in genetic diversity of any introduced marine amphipod. Additional intensive sampling of this species, including both native and non-native populations, and detailed temporal studies are still necessary to properly understand how genetic diversity influences the introduction and survival of P. pusilla in invaded areas.

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Research Article Thu, 20 Jun 2019 09:54:05 +0300
Temporal activity of rural free-ranging dogs: implications for the predator and prey species in the Brazilian Atlantic Forest https://neobiota.pensoft.net/article/30645/ NeoBiota 45: 55-74

DOI: 10.3897/neobiota.45.30645

Authors: William Douglas Carvalho, Luís Miguel Rosalino, Maíra Sant’Ana M. Godoy, Marília F. Giorgete, Cristina Harumi Adania, Carlos E. Lustosa Esbérard

Abstract: Domestic or free-ranging dogs (Canis lupus familiaris) can have deleterious effects on wildlife, acting as predators or competitors to native species. These impacts can be highly important in fragmented pristine habitats or well-preserved areas located in human dominated landscapes and where biodiversity values are usually high, such as those in southeastern Brazil. Here we explored the level of overlap or mismatch in the distributions of activity patterns of rural free-ranging dogs and potential wild prey (Didelphis aurita, Cuniculus paca; Sylvilagus brasiliensis) and a wild predator (Leopardus pardalis) in areas of Atlantic Forest in southeastern Brazil. We further explored the possible influence of the wild predator on the dog presence pattern detected in the territory analyzed. Our camera-trap data (714 camera-trap days) showed that while rural free-ranging dogs display a cathemeral activity pattern, with activity peaks at dusk and dawn, ocelot and prey species are mainly nocturnal. Moreover, we found no evidence of an effect of ocelot presence, the distance to human houses and the presence of native forests on site occupancy by dogs. The ocelot activity patterns in this study were similar to those already reported in previous studies. On the other hand, previous studies have indicated that that free-ranging dogs are often reported to be more diurnal, and it seems that the rural free-ranging dogs in our study area may have adjusted their behaviour to be more active at dawn and dusk periods. This might be to both maintain some overlap with potential prey, e.g. Sylvilagus brasiliensis, and also to avoid ocelots by being less active in periods when this predator is more active (which also coincides with peaks in activity for potential prey species). We hypothesize that the presence of ocelots might be influencing the temporal niche dimension of rural free-ranging dogs. As a sustainable management strategy, we propose conserving territories to promote the presence of medium to large predators in natural areas, in order to control free-ranging dogs and protect their vertebrate prey species.

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Research Article Mon, 22 Apr 2019 10:20:42 +0300
Whistling invaders: Status and distribution of Johnstone’s Whistling frog (Eleutherodactylus johnstonei Barbour, 1914), 25 years after its introduction to Colombia https://neobiota.pensoft.net/article/33515/ NeoBiota 45: 39-54

DOI: 10.3897/neobiota.45.33515

Authors: Franziska Leonhardt, Juan David Jimenez-Bolaño, Raffael Ernst

Abstract: Despite increased attention to the problem of alien amphibian invasions, systematic assessments of the actual invasion status and potential, required to estimate possible environmental and economic impacts of introduced species, are often missing. A prime example is Johnstone’s Whistling Frog (Eleutherodactylus johnstonei), a Caribbean native that now occurs widely throughout the South American mainland, including Colombia. We conducted the first systematic and comprehensive countrywide assessment of the introduction status of the species in Colombia, combining both intensive field surveys, as well as a first population genetic analysis. The species was strictly confined to urban habitats with specific environmental conditions (plant nurseries and private gardens) and did not show any signs of dispersal into the extra-urban matrix. Genetic data support previously hypothesised independent introduction events in the Andes and along the Caribbean Coast and shed light on potential dispersal pathways. The results of this study challenge both the active spread, as well as the broad environmental tolerance hypothesis previously suggested, to explain the observed range extension. A critical reassessment of the categorisation of the species as highly invasive under IUCN-ISSG standards is required.

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Short Communication Thu, 18 Apr 2019 12:38:14 +0300
The dark side of facilitation: native shrubs facilitate exotic annuals more strongly than native annuals https://neobiota.pensoft.net/article/33771/ NeoBiota 44: 75-93

DOI: 10.3897/neobiota.44.33771

Authors: Jacob E. Lucero, Taylor Noble, Stephanie Haas, Michael Westphal, H. Scott Butterfield, Christopher J. Lortie

Abstract: Positive interactions enhance biodiversity and ecosystem function, but can also exacerbate biological invasions. Facilitation of exotic invaders by exotic foundation species (invasional meltdown) has been studied extensively, but facilitation of exotic invaders by native foundation species has attracted less attention. Specifically, very few studies have examined the extent that native foundation species facilitate native and exotic competitors. Understanding the processes that mediate interactions between native and exotic species can help explain, predict, and improve management of biological invasions. Here, we examined the effects of native foundation shrubs on the relative abundance of the annual plant community – including native and exotic taxa – from 2015–2018 in a desert ecosystem at Carrizo Plain National Monument, California, USA (elevation: 723 m). Shrub effects varied by year and by the identity of annual species, but shrubs consistently enhanced the abundance of the annual plant community and facilitated both native (n=17 species) and exotic (n=4 species) taxa. However, at the provenance level, exotic annuals were facilitated 2.75 times stronger in abundance than native annuals, and exotic annuals were always more abundant than natives both near and away from shrubs. Our study reaffirms facilitation as an important process in the organisation of plant communities and confirms that both native and exotic species can form positive associations with native foundation species. However, facilitation by native foundation species can exacerbate biological invasions by increasing the local abundance of exotic invaders. Thus, the force of facilitation can have a dark side relevant to ecosystem function and management.

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Data Paper Fri, 5 Apr 2019 10:36:22 +0300
Efficacy of Kamona strain Deladenus siricidicola nematodes for biological control of Sirex noctilio in North America and hybridisation with invasive conspecifics https://neobiota.pensoft.net/article/30402/ NeoBiota 44: 39-55

DOI: 10.3897/neobiota.44.30402

Authors: Tonya D. Bittner, Nathan Havill, Isis A.L. Caetano, Ann E. Hajek

Abstract: Sirex noctilio is an invasive woodwasp that, along with its symbiotic fungus, has killed pine trees (Pinus spp.) in North America and in numerous countries in the Southern Hemisphere. We tested a biological control agent in North America that has successfully controlled S. noctilio in Oceania, South Africa, and South America. Deladenus siricidicola nematodes feed on the symbiotic white rot fungus Amylostereum areolatum and can switch to being parasitic on S. noctilio. When parasitic, the Kamona nematode strain can sterilise the eggs of S. noctilio females. However, in North America, a different strain of D. siricidicola (NA), presumably introduced along with the woodwasp, parasitises but does not sterilise S. noctilio. We tested the sterilising Kamona biological control strain of D. siricidicola against S. noctilio in North America. Interactions between the biological control strain and the NA strain could include competitive exclusion, co-infection within hosts or hybridisation. We reared D. siricidicola Kamona on an A. areolatum strain native to North America (IGS-BE) and another strain (IGS-BDF) used commercially to mass-produce the nematode in Australia. We inoculated Kamona reared on either strain of A. areolatum into logs infested with S. noctilio larvae and compared parasitism rates against control logs. Individual nematodes were isolated from S. noctilio hemocoels and from sterilised eggs and were genotyped with eight microsatellite loci. A high rate of parasitisation of S. noctilio by D. siricidicola NA was found for all treatments and we found evidence of both co-infection and hybridisation. Surprisingly, sterilisation rates were not related to the rates of parasitisation by D. siricidicola Kamona.

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Research Article Thu, 4 Apr 2019 16:48:31 +0300
Does invasive species research use more militaristic language than other ecology and conservation biology literature? https://neobiota.pensoft.net/article/32925/ NeoBiota 44: 27-38

DOI: 10.3897/neobiota.44.32925

Authors: Rachel M. Janovsky, Eric R. Larson

Abstract: Invasive species research has been criticised for a reliance on hyperbolic or sensationalistic language, including the use of militaristic language that dates to the popularisation of this concept. We sought to evaluate whether the invasive species literature used more militaristic language than other literature across the fields of ecology and conservation biology, given that many research areas in these fields (e.g. competition) may routinely use militaristic language. We compared militaristic language use in journal articles on invasive species or other topics across both applied and basic science journals in the fields of ecology and conservation biology. We further restricted our study to papers where lead-authors were located at institutions in the United States, to evaluate whether militaristic language use varied over peace time and conflict periods for this country. We found no significant differences in the percentage of journal articles that used any militaristic language between either invasive species research or research on other topics, but we did find that invasive species research used a greater frequency (count) of militaristic language per article than research on other topics. We also found that basic rather than applied science journals were more likely to use militaristic language and we detected no significant effect of time period on the usage of militaristic language in the ecology and conservation biology literature. Researchers working on invasive species should continue to be conscientious about their language use on this occasionally controversial topic, particularly in basic science journals.

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Research Article Thu, 4 Apr 2019 10:08:56 +0300
Differential germination strategies of native and introduced populations of the invasive species Plantago virginica https://neobiota.pensoft.net/article/30392/ NeoBiota 43: 101-118

DOI: 10.3897/neobiota.43.30392

Authors: Xinyu Xu, Lorne Wolfe, Jeffrey Diez, Yi Zheng, Hui Guo, Shuijin Hu

Abstract: Germination strategies are critically important for the survival, establishment and spread of plant species. Although many plant traits related to invasiveness have been broadly studied, the earliest part of the life cycle, germination, has received relatively little attention. Here, we compared the germination patterns between native (North America) and introduced (China) populations of Plantago virginica for four consecutive years to examine whether there has been adaptive differentiation in germination traits and how these traits are related to local climatic conditions. We found that the introduced populations of P. virginica had significantly higher germination percentages and faster and shorter durations of germination than native populations. Critically, the native populations had a significantly larger proportion of seeds that stayed dormant in all four years, with only 60% of seeds germinating in year 1 (compared to >95% in introduced populations). These results demonstrate striking differences in germination strategies between native and introduced populations which may contribute to their successful invasion. Moreover, the germination strategy of P. virginica in their native range exhibited clear geographical variation across populations, with trends towards higher germination percentages at higher latitudes and lower annual mean temperatures and annual precipitation. In the introduced range, however, their germination strategies were more conserved, with less variation amongst populations, suggesting that P. virginica may have experienced strong selection for earlier life history characteristics. Our findings highlight the need to examine the role of rapid evolution of germination traits in facilitating plant invasion.

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Research Article Tue, 19 Mar 2019 10:13:25 +0200
The interplay between propagule pressure, seed predation and ectomycorrhizal fungi in plant invasion https://neobiota.pensoft.net/article/30978/ NeoBiota 42: 45-58

DOI: 10.3897/neobiota.42.30978

Authors: Jaime Moyano, Mariana C. Chiuffo, Nahuel Policelli, Martin A. Nuñez, Mariano A. Rodriguez-Cabal

Abstract: There are many hypotheses aiming to explain invasion success, but evaluating individual hypotheses in isolation may hinder our ability to understand why some species invade and others fail. Here we evaluate the interaction between propagule pressure, seed predation and missed mutualism in the invasion success of the pine, Pinus ponderosa. We evaluated the independent and interactive effects of propagule pressure and seed predation at increasing distances from a pine plantation. Additionally, because pines are obligate mutualists with ectomycorrhizal fungi (EMF) and pine invasions fail in the absence of their EMF symbionts, we evaluated EMF availability through a growth chamber bioassay. In this bioassay we measured root colonization by EMF with soil samples collected from the different distances from the plantation. We found that propagule pressure overwhelms seed predation only at the edge of the pine plantation, while seed predation overcomes propagule pressure at 25 m and further distances from the plantation. We also found that EMF root colonization decreases with distance from the plantation. However, pine roots were colonized up to 200 m from the plantation, suggesting that EMF may not be hindering invasion, at least not on the scale of this experiment. Taken together our results demonstrate that seed predation may be limiting the invasion of P. ponderosa in the study region as propagule pressure only overcomes seed predation at the plantation edge. Here we provide evidence of how strong biotic resistance can suppress an invasion, regardless of the variation in propagule pressure and the availability of mutualists.

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Research Article Mon, 18 Feb 2019 10:00:43 +0200
Variation in phenology and overall performance traits can help to explain the plant invasion process amongst Mediterranean ecosystems https://neobiota.pensoft.net/article/29965/ NeoBiota 41: 67-89

DOI: 10.3897/neobiota.41.29965

Authors: Irene Martín-Forés, Miguel A. Casado, Isabel Castro, Alejandro del Pozo, Marco Molina-Montenegro, José M De Miguel, Belén Acosta-Gallo

Abstract: Plant traits such as phenological development, growth rate, stress tolerance and seeds production may play an important role in the process of acclimatisation to new environments for introduced plants. Experiments that distinguish phenotypic plasticity from ecotypic differentiation would allow an understanding of the role of plant traits in the invasion process. We quantified the variation in phenological and overall performance traits associated with the invasion process for three herbaceous species native to Spain and invasive to Chile (Trifolium glomeratum, Hypochaeris glabra and Leontodon saxatilis). We grew plants from native and exotic populations along rainfall gradients in outdoor common gardens, located in the native and the introduced ranges and measured plant survival, phenology (days to flowering), biomass and seed output. Days to flowering was positively correlated with precipitation of the origin population for T. glomeratum and the native populations of H. glabra, but this pattern was not adaptive, as it was not associated with an increase in performance traits of these species. Phenology may instead reflect ecotypic differentiation to the environmental conditions of the original populations. Comparison between ranges (i.e. performance in both common gardens) was only possible for L. saxatilis. This species showed little variation in phenology and both native and exotic populations had higher fitness in the introduced range. This suggests that plasticity enhances invasiveness through increased propagule pressure in the novel environment. Our findings highlight the utility of common garden experiments in examining patterns of phenological and performance traits that relate to species invasiveness.

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Research Article Fri, 21 Dec 2018 09:48:50 +0200
Environmental harshness drives spatial heterogeneity in biotic resistance https://neobiota.pensoft.net/article/28558/ NeoBiota 40: 87-105

DOI: 10.3897/neobiota.40.28558

Authors: Basil V. Iannone III, Kevin M. Potter, Qinfeng Guo, Insu Jo, Christopher M. Oswalt, Songlin Fei

Abstract: Ecological communities often exhibit greater resistance to biological invasions when these communities consist of species that are not closely related. The effective size of this resistance, however, varies geographically. Here we investigate the drivers of this heterogeneity in the context of known contributions of native trees to the resistance of forests in the eastern United States of America to plant invasions. Using 42,626 spatially referenced forest community observations, we quantified spatial heterogeneity in relationships between evolutionary relatedness amongst native trees and both invasive plant species richness and cover. We then modelled the variability amongst the 91 ecological sections of our study area in the slopes of these relationships in response to three factors known to affect invasion and evolutionary relationships –environmental harshness (as estimated via tree height), relative tree density and environmental variability. Invasive species richness and cover declined in plots having less evolutionarily related native trees. The degree to which they did, however, varied considerably amongst ecological sections. This variability was explained by an ecological section’s mean maximum tree height and, to a lesser degree, SD in maximum tree height (R2GLMM = 0.47 to 0.63). In general, less evolutionarily related native tree communities better resisted overall plant invasions in less harsh forests and in forests where the degree of harshness was more homogenous. These findings can guide future investigations aimed at identifying the mechanisms by which evolutionary relatedness of native species affects exotic species invasions and the environmental conditions under which these effects are most pronounced.

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Research Article Tue, 4 Dec 2018 09:10:17 +0200
Provenance of invaders has scale-dependent impacts in a changing wetland ecosystem https://neobiota.pensoft.net/article/28914/ NeoBiota 40: 51-72

DOI: 10.3897/neobiota.40.28914

Authors: Kathryn L. Amatangelo, Lee Stevens, Douglas A. Wilcox, Stephen T. Jackson, Dov F. Sax

Abstract: Exotic species are associated with a variety of impacts on biodiversity, but it is unclear whether impacts of exotic species differ from those of native species with similar growth forms or native species invading disturbed sites. We compared presence and abundance of native and exotic invaders with changes in wetland plant species diversity over a 28-year period by re-surveying 22 ponds to identify factors correlated with observed changes. We also compared communities found within dense patches of native and exotic emergent species with similar habits. Within patches, we found no categorical diversity differences between areas dominated by native or exotic emergent species. At the pond scale, the cover of the exotic grass Phragmites australis best predicted change in diversity and evenness over time, likely owing to its significant increase in coverage over the study period. These changes in diversity and evenness were strongest in younger, less successionally-advanced ponds. Changes associated with cover of P. australis in these ponds were not consistent with expected diversity decreases, but instead with a dampening of diversity gains, such that the least-invaded ponds increased in diversity the most over the study period. There were more mixed effects on evenness, ranging from a reduction in evenness gains to actual losses of evenness in the ponds with highest invader cover. In this wetland complex, the habit, origin and invasiveness of species contribute to diversity responses in a scale- and context-dependent fashion. Future efforts to preserve diversity should focus on preventing the arrival and spread of invaders that have the potential to cover large areas at high densities, regardless of their origin. Future studies should also investigate more thoroughly how changes in diversity associated with species invasions are impacted by other ongoing ecosystem changes.

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Research Article Mon, 19 Nov 2018 09:45:21 +0200
Forecasting the global extent of invasion of the cereal pest Spodoptera frugiperda, the fall armyworm https://neobiota.pensoft.net/article/28165/ NeoBiota 40: 25-50

DOI: 10.3897/neobiota.40.28165

Authors: Regan Early, Pablo González-Moreno, Sean T. Murphy, Roger Day

Abstract: Fall armyworm, Spodoptera frugiperda, is a crop pest native to the Americas, which has invaded and spread throughout sub-Saharan Africa within two years. Recent estimates of 20–50% maize yield loss in Africa suggest severe impact on livelihoods. Fall armyworm is still infilling its potential range in Africa and could spread to other continents. In order to understand fall armyworm’s year-round, global, potential distribution, we used evidence of the effects of temperature and precipitation on fall armyworm life-history, combined with data on native and African distributions to construct Species Distribution Models (SDMs). We also investigated the strength of trade and transportation pathways that could carry fall armyworm beyond Africa. Up till now, fall armyworm has only invaded areas that have a climate similar to the native distribution, validating the use of climatic SDMs. The strongest climatic limits on fall armyworm’s year-round distribution are the coldest annual temperature and the amount of rain in the wet season. Much of sub-Saharan Africa can host year-round fall armyworm populations, but the likelihoods of colonising North Africa and seasonal migrations into Europe are hard to predict. South and Southeast Asia and Australia have climate conditions that would permit fall armyworm to invade. Current trade and transportation routes reveal Australia, China, India, Indonesia, Malaysia, Philippines and Thailand face high threat of fall armyworm invasions originating from Africa.

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Research Article Fri, 9 Nov 2018 15:12:54 +0200
Book Review: The Green Menace – Emerald Ash Borer and the Invasive Species Problem by Jordan D. Marché II https://neobiota.pensoft.net/article/24431/ NeoBiota 37: 51-54

DOI: 10.3897/neobiota.37.24431

Authors: Marcel Rejmanek

Abstract: N/A

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Book Review Tue, 6 Mar 2018 09:49:30 +0200
Comparing functional traits and abundance of invasive versus native woodwasps https://neobiota.pensoft.net/article/14953/ NeoBiota 36: 39-55

DOI: 10.3897/neobiota.36.14953

Authors: Ann E. Hajek, Jacob C. Henry, Christopher R. Standley, Christopher J. Foelker

Abstract: Functional traits are useful for comparing the resource use of invasive and native species, with goals of identifying resource overlap to predict competitive interactions. The invasion of northeastern North America by the woodwasp Sirex noctilio has resulted in competition with the native congeneric Sirex nigricornis for suppressed and weakened pines. We compared sizes of adults, venom glands, fecundity, tree species use, voltinism and abundance of the invasive woodwasp S. noctilio with the native S. nigricornis in northeastern North American pines. Rearing adults from attacked pines showed that these species used the same tree species but S. noctilio were far more abundant, especially with increasing time since establishment. Adults of the invasive S. noctilio were larger than S. nigricornis, female S. noctilio had larger glands carrying phytotoxic venom in relation to body size, average-sized S. noctilio females carried more eggs, and S. noctilio developed faster than S. nigricornis. Sirex noctilio was the dominant woodwasp infesting suppressed pines in our study areas. We hypothesize that the future abundance of S. nigricornis could depend in part on the availability of wood for oviposition by this native that is not available or acceptable to the earlier-emerging S. noctilio.

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Research Article Fri, 3 Nov 2017 08:41:55 +0200
Biotic constraints on the establishment and performance of native, naturalized, and invasive plants in Pacific Northwest (USA) steppe and forest https://neobiota.pensoft.net/article/10820/ NeoBiota 34: 21-40

DOI: 10.3897/neobiota.34.10820

Authors: Brian M. Connolly, Jennifer Powers, Richard N. Mack

Abstract: Factors that cause differential establishment among naturalized, invasive, and native species are inadequately documented, much less often quantified among different communities. We evaluated the effects of seed addition and disturbance (i.e., understory canopy removal) on the establishment and seedling biomass among two naturalized, two invasive, and two native species (1 forb, 1 grass in each group) within steppe and low elevation forest communities in eastern Washington, USA. Establishment within each plant immigrant class was enhanced by seed addition: naturalized species showed the greatest difference in establishment between seed addition and no seed addition plots, native and invasive species establishment also increased following seed addition but not to the same magnitude as naturalized species. Within seed addition plots, understory canopy disturbance resulted in significant increases in plant establishment (regardless of plant immigration class) relative to undisturbed plots and the magnitude of this effect was comparable between steppe and adjacent forest. However, regardless of disturbance treatment fewer invasive plants established in the forest than in the steppe, whereas native and naturalized plant establishment did not differ between the habitats. Individual biomass of naturalized species were consistently greater in disturbed (canopy removed) versus undisturbed control plots and naturalized species were also larger in the steppe than in the forest at the time of harvest. Similar trends in plant size were observed for the native and invasive species, but the differences in biomass for these two immigration classes between disturbance treatments and between habitats were not significant. We found that strong limitations of non-native species is correlated with intact canopy cover within the forest understory, likely driven by the direct or indirect consequences of low light transmittance through the arboreal and understory canopy. Considered collectively, our results demonstrate how seed limitation and intact plant ground cover can limit the abundance and performance of naturalized species in Pacific Northwest steppe and low elevation forest, suggesting that local disturbance in both habitats creates microsites for these species to establish and survive. Future studies evaluating interactions between multiple barriers to establishment using more representatives from each immigration class will further reveal how biotic interactions ultimately influence the demography and distribution of non-native plants within these communities.

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Research Article Thu, 23 Feb 2017 10:55:53 +0200
Range expansion drives the evolution of alternate reproductive strategies in invasive fire ants https://neobiota.pensoft.net/article/10300/ NeoBiota 33: 67-82

DOI: 10.3897/neobiota.33.10300

Authors: Jackson A. Helms IV, Eli S. Bridge

Abstract: Many species are expanding their ranges in response to climate changes or species introductions. Expansion-related selection likely drives the evolution of dispersal and reproductive traits, especially in invasive species introduced into novel habitats. We used an agent-based model to investigate these relationships in the red imported fire ant, Solenopsis invicta, by tracking simulated populations over 25 years. Most colonies of this invasive species produce two types of queens practicing alternate reproductive strategies. Claustral queens found new colonies in vacant habitats, while parasitic queens take over existing colonies whose queens have died. We investigated how relative investment in the two queen types affects population demography, habitat occupancy, and range expansion. We found that parasitic queens extend the ecological lifespan of colonies, thereby increasing a population’s overall habitat occupancy as well as average colony size (number of workers) and territory size. At the same time, investment in parasitic queens slowed the rate of range expansion by diverting investment from claustral queens. Divergent selection regimes caused edge and interior populations to evolve different levels of reproductive investment, such that interior populations invested heavily in parasitic queens whereas those at the edge invested almost entirely in claustral queens. Our results highlight factors shaping ant life histories, including the evolution of social parasitism, and have implications for the response of species to range shifts.

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Research Article Fri, 27 Jan 2017 12:27:12 +0200
Small details of big importance: Carbon mass determination in the invasive cladoceran Cercopagis pengoi (Ostroumov, 1891) by the high temperature combustion method https://neobiota.pensoft.net/article/9823/ NeoBiota 33: 19-32

DOI: 10.3897/neobiota.33.9823

Authors: Irena V. Telesh

Abstract: Carbon mass of the non-indigenous predatory fishhook water flea Cercopagis pengoi (Ostroumov, 1891) from the eastern Gulf of Finland, the Baltic Sea, was for the first time measured using the high temperature combustion method. Prior to the analysis, individual dry weight of Cercopagis was determined; altogether ca. 500 organisms were examined. Mean individual dry weight of C. pengoi for July-September was estimated as 34.0 µg; carbon mass averaged 15.8 µg; carbon content, calculated as percent of dry weight, averaged 43.4%. Those values varied over months, mainly because of different population structure of C. pengoi and variation in their diet due to seasonal dynamics of the food objects. However, relations between carbon mass and dry weight for different months did not differ statistically (p<0.001). Therefore, the general polynomial regressions (k=2), describing carbon mass-to-dry weight and carbon content-to-dry weight relationships, were calculated for the entire dataset of individual measurements of C. pengoi body metrics. These data will contribute to adequate evaluation of food web structure and ecosystem alterations in various water bodies invaded by C. pengoi which has got a strong potential to pelagic food web transformations that may impact the overall energy balance and decrease the size of fish stocks.

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Research Article Fri, 27 Jan 2017 10:01:50 +0200
Evaluating simplistic methods to understand current distributions and forecast distribution changes under climate change scenarios: an example with coypu (Myocastor coypus) https://neobiota.pensoft.net/article/8884/ NeoBiota 32: 107-125

DOI: 10.3897/neobiota.32.8884

Authors: Catherine S. Jarnevich, Nicholas E. Young, Trevor R. Sheffels, Jacoby Carter, Mark D. Sytsma, Colin Talbert

Abstract: Invasive species provide a unique opportunity to evaluate factors controlling biogeographic distributions; we can consider introduction success as an experiment testing suitability of environmental conditions. Predicting potential distributions of spreading species is not easy, and forecasting potential distributions with changing climate is even more difficult. Using the globally invasive coypu (Myocastor coypus [Molina, 1782]), we evaluate and compare the utility of a simplistic ecophysiological based model and a correlative model to predict current and future distribution. The ecophysiological model was based on winter temperature relationships with nutria survival. We developed correlative statistical models using the Software for Assisted Habitat Modeling and biologically relevant climate data with a global extent. We applied the ecophysiological based model to several global circulation model (GCM) predictions for mid-century. We used global coypu introduction data to evaluate these models and to explore a hypothesized physiological limitation, finding general agreement with known coypu distribution locally and globally and support for an upper thermal tolerance threshold. Global circulation model based model results showed variability in coypu predicted distribution among GCMs, but had general agreement of increasing suitable area in the USA. Our methods highlighted the dynamic nature of the edges of the coypu distribution due to climate non-equilibrium, and uncertainty associated with forecasting future distributions. Areas deemed suitable habitat, especially those on the edge of the current known range, could be used for early detection of the spread of coypu populations for management purposes. Combining approaches can be beneficial to predicting potential distributions of invasive species now and in the future and in exploring hypotheses of factors controlling distributions.

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Research Article Wed, 4 Jan 2017 19:00:00 +0200
Corrigendum: A subcontinental view of forest plant invasions https://neobiota.pensoft.net/article/8785/ NeoBiota 31: 105-106

DOI: 10.3897/neobiota.31.8785

Authors: Christopher M. Oswalt, Songlin Fei, Qinfeng Guo, Basil V. Iannone, Sonja N. Oswalt, Bryan C. Pijanowski, Kevin M. Potter

Abstract: Due to an oversight during the review process, an incorrect figure in Oswalt et al. (2015) was printed as Fig. 2. The mapped species represented in Oswalt et al. (2015) is Triadica sebifera or Chinese tallow. The correct Fig. 2 is reproduced below.

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Corrigenda Wed, 14 Sep 2016 16:18:10 +0300
Importance of soil and plant community disturbance for establishment of Bromus tectorum in the Intermountain West, USA https://neobiota.pensoft.net/article/7119/ NeoBiota 30: 111-125

DOI: 10.3897/neobiota.30.7119

Authors: A. Joshua Leffler, Thomas A. Monaco, Jeremy J. James, Roger L. Sheley

Abstract: The annual grass Bromus tectorum has invaded millions of hectares in western North America and has transformed former perennial grass and shrub-dominated communities into annual grasslands. Fire plays a key role in the maintenance of B. tectorum on the landscape but the type of disturbance responsible for initial invasion is less well understood. We conducted an experiment in a perennial shrub/grass/forb community in eastern Idaho, USA to examine the roles of plant community and soil disturbance on B. tectorum emergence and establishment prior to state-changing fires. Our experiment consisted of a plant community disturbance treatment where we (1) removed the shrub component, (2) removed the grass/forb component, or (3) removed all shrubs, grasses, and forbs. We followed this treatment with seeding of B. tectorum onto the soil surface that was (1) intact, or (2) disturbed. Each experimental plot had an associated control with no plant community disturbance but was seeded in the same manner. The experiment was replicated 20 times in two sites (high and low aboveground biomass). We measured emergence by counting seedlings in late spring and establishment by counting, removing, and weighing B. tectorum individuals in mid-summer. We also examined the influence of plant community disturbance on the soil environment by measuring extractable NH4+ and NO3– four times each summer. Soil disturbance greatly influenced the number of B. tectorum individuals that emerged each spring. Plant community disturbance, specifically disturbance of the grass/forb component, increased N availability in the late growing season and biomass of B. tectorum the following summer. We conclude that soil disturbance and plant community disturbance interact to promote the initial invasion of B. tectorum in Intermountain West valley ecosystems.

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Research Article Thu, 23 Jun 2016 17:14:51 +0300
Pathway risk analysis of weed seeds in imported grain: A Canadian perspective https://neobiota.pensoft.net/article/7502/ NeoBiota 30: 49-74

DOI: 10.3897/neobiota.30.7502

Authors: Claire E. Wilson, Karen L. Castro, Graham B. Thurston, Andrea Sissons

Abstract: The risk of introducing weeds to new areas through grain (cereals, oilseeds and pulses) intended for processing or consumption is typically considered less than that from seed or plants for planting. However, within the range of end uses for grain, weed risk varies significantly and should not be ignored. In this paper, we discuss pathway risk analysis as a framework to examine the association of weed seeds with grain commodities throughout the production process from field to final end use, and present inspection sampling data for grain crops commonly imported to Canada. In the field, weed seed contamination of grain crops is affected by factors such as country of origin, climate, biogeography and production and harvesting practices. As it moves toward export, grain is typically cleaned at a series of elevators and the effectiveness and degree of cleaning are influenced by grain size, shape and density as well as by grade requirements. In cases where different grain lots are blended, uncertainty may be introduced with respect to the species and numbers of weed seed contaminants. During transport and storage, accidental spills and cross-contamination among conveyances may occur. At the point of import to Canada, inspection sampling data show that grain shipments contain a variety of contaminants including seeds of regulated weeds and species that represent new introductions. However, grain cleaning and processing methods tailored to end use at destination also affect the presence and viability of weed seeds. For example, grains that are milled or crushed for human use present a lower risk of introducing weed seeds to new environments than grains that undergo minimal or no processing for livestock feed, or screenings that are produced as a by-product of grain cleaning. Pathway risk analysis allows each of these stages to be evaluated in order to characterize the overall risk of introducing weeds with particular commodities, and guide regulatory decisions about trade and plant health.

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Research Article Thu, 23 Jun 2016 10:24:20 +0300