Arthropods play an important role in providing ecosystem services and are integral to terrestrial food webs. Given their importance, recent evidence suggesting widespread declines in arthropod populations has received considerable attention from scientists, politicians, and the public. While the declines of specific groups of insects (e.g., Hymenoptera, Lepidoptera) have been documented in North America, few studies have investigated temporal trends in populations across a range of arthropod taxa in multiple ecosystem types. To address this knowledge gap, we examined long-term trends in arthropod abundance in Illinois using a 21-year data set of standardized sweep net samples taken in >500 randomly selected forest, grassland, and wetland sites.
Results/Conclusions
The abundance of many arthropod Orders has declined significantly during the 21 years of data collection, but the rate of decline has varied among ecosystem types. These declines suggest that recent international evidence of widespread arthropod declines is not isolated. Our results are alarming given the importance of arthropods in functioning ecosystems and further research into understanding these declines could provide information for ways to slow or reverse current declines.