Division of total costs of invasive species in Australia relative to a reliability (high: dark grey or low: light grey) and the form of implementation (i.e. whether the cost estimate was realised [observed] or predicted [potential]) b costs according to major kingdoms. The number of unique database entries (n) in each category is indicated in brackets.

a sum of all costs according to attributable major political unit (States and Territories) b sum of highly reliable costs only by political unit c relationship between the number of database entries and all cost estimates by political unit – this also includes the estimate for ‘Australia’ (‘AUS’; not directly attributable to a single State or Territory). The power-law relationship is also shown (evidence ratio = 18013, R² = 0.90) d relationship between number of database entries for highly reliable costs estimates by political unit (evidence ratio = 38550, R² = 0.91). Abbreviations: ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; QLD = Queensland; SA = South Australia; TAS = Tasmania; VIC = Victoria; WA = Western Australia; AUS = nation-wide or not specified to which political unit the estimate belongs. ‘Australian territory’ refers to regions outside State/Territory jurisdication (e.g. Christmas Island, Lord Howe Island).

Sum of all (black) and highly reliable-only (grey) costs according to a taxonomic class b by plant species c by mammal species and d by insect species. We generally ordered these by the highly reliable costs, but, in some cases where there were no highly reliable costs for a particular category, we placed the category in the order suggested by total costs.

The costliest species (or group of species) per State/Territory. The left axis shows the percentage of the State’s/Territory’s total highly reliable, observed costs attributable to the species indicated and the right axis shows the value of these species in $US billion (2017 value). For all States/Territories, except Australian Capital Territory (ACT), Northern Territory (NT) and Tasmania, the costliest category is in fact diverse/unspecified. State/Territory abbreviations and species icons refer to: ACT = Australian Capital Territory (cats, foxes, rabbits); NSW = New South Wales (foxes); NT = Northern Territory (banana freckle disease Phyllosticta cavendishii), QLD = Queensland (red imported fire ants); SA = South Australia (common heliotrope Heliotropium europaeum); TAS = Tasmania (ragwort Senecio jacobaea); VIC = Victoria (common heliotrope); WA = Western Australia (annual ryegrass Lolium rigidum).

Proportional attribution of costs by species per State and Territory (highly reliable, observed costs only; refer also to Fig. 4). State/Territory abbreviations: ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory, QLD = Queensland; SA = South Australia; TAS = Tasmania; VIC = Victoria; WA = Western Australia. The full list of species (common and scientific names) is provided in Suppl. material 1: Table S1.

a sum of all (black) and reliable-only (grey) costs (log₁₀ scale) according the impacted environment b cost type and (c) the major impacted sector.

a raw annual costs for all costs (black) and reliable, observed costs (grey). Also shown are the decadal and overall means b predicted annual costs across Australia from 1970 to 2020 for all costs and c reliable, observed costs only. Fitted models include OLS_l = linear ordinary least-squares, OLS_q = quadratic ordinary least-squares, RR_l = linear robust regression, RR_q = quadratic robust regression, GAM = general additive model. Also shown in each panel are wAIC $₂₀₁₇ = Akaike’s information criterion-weighted (wAIC)-average of the predicted annual cost in 2017 (all costs; OLS_l, OLS_q, GAM only), wRMSE $₂₀₁₇ = root mean-squared error-weighted average of the predicted annual cost in 2017 (all costs; all models), wAIC $₂₀₁₇, and wRMSE $₂₀₁₇ (reliable, observed costs only).