The effects of climate change, land use change, and pesticide use on butterfly trends across the United States

Insect declines have been widely documented across taxonomic groups and regions, threatening vital ecosystem services. However, identifying the relative contributions and interactions of global change drivers remains challenging due to a scarcity of long-term, broad-scale datasets. To address this gap, we integrated butterfly monitoring data collected by community scientists from 35 programs across the United States, encompassing over 12 million individual records from 2000–2020. Using this large-scale community science dataset, we estimated species-specific abundance trends at sites across the contiguous United States with at least ten years of standardized monitoring data. We then applied a Bayesian post-hoc analysis to assess the relative influence of three major environmental stressors—climate change, land use change, and pesticide use—on butterfly population trends. Our models also evaluate interactions among these stressors and assess how their effects vary across ecoregions. Preliminary results reveal distinct spatial patterns in stressor impacts, highlighting the importance of considering regional context when designing conservation strategies. We also share how we are working with conservation practitioners and policymakers to translate these insights into actionable strategies for insect conservation. This work demonstrates the power of integrating large-scale community science data with spatial environmental datasets to uncover the complex drivers of insect population change, and to support evidence-based conservation and management.