Roadside Surveys as a Method for Nonlethal Insect Monitoring

Insects are a megadiverse group of organisms, which makes them difficult to survey without large, lethal collections. At the same time, we have increasing concerns about declines in insect biomass and diversity, which could have serious implications for ecosystem functioning. Current methods of insect monitoring are high in cost and labor and expertise intensive, often requiring large amounts of physical storage space that must be maintained indefinitely, making them difficult to sustain to the degree and extent that would be required to track population level changes in insect species at local or regional scales. Traditional methods can also be slow, sometimes requiring years to process and identify all the specimens collected. Moreover, there are concerns about the potential role of destructive sampling methods in exacerbating already declining groups of insects. Due to this, nonlethal, sustainable, rapid, and low‐cost methods of monitoring and surveying are needed. I combined modern technological methods, including photographic vouchers and community science programs (i.e., iNaturalist), and surveys of insect roadkill to test as a potential nonlethal method of monitoring insect populations. I repeated these surveys on a weekly basis under appropriate weather conditions along a highway bridge for the duration of a year and recorded 4917 specimens with 3061 specimens (62.2%) identified to 152 species, and an additional 1506 (30.6%) to 111 genera. I found this method promising for nonlethal monitoring because photographic vouchers required less time and space to use and maintain, and using the expertise of community scientists lowered initial barriers to participation. This method also had a rapid turnaround time and was straightforward to repeat without adding significant bias. The roadkill surveys avoided additional insect mortality as they involved insects that had already been killed by vehicular traffic.