County-level distributions of spotted lanternfly (SLF) in the eastern USA. Distribution of SLF detections and establishments by year based on USDA Animal and Plant Health Inspection Service and Pennsylvania Department of Agriculture visual survey data. Counties with hash marks had SLF detections that failed to establish. We define a county as invaded when the county experiences at least two consecutive years of SLF detection, and define year invaded as the first of those two consecutive years. Counties with white color were not surveyed.