Incidental capture of Bombus species in traps: A national survey

It is well known that Bombus are commonly collected as bycatch in insect traps; however, no study has assessed regional variation in bycatch composition or determined whether the trapped Bombus community differs from the community in the landscape. Therefore, our objective was to characterize the nature and scope of Bombus bycatch throughout the U.S. to better understand large-scale regional effects of traps on these pollinator communities. We examined bycatch collected biweekly in multicolored plastic bucket traps used to detect invasive Lepidopterans within 272 agricultural fields throughout Florida, Indiana, Kansas, Kentucky, Maryland, South Carolina, Utah, and West Virginia between April and October in 2018 and 2019. Most of the bycatch was obtained from traps placed in vegetable fields due to the importance of pollination services in these crops. A total of 3,238 Bombus representing 17 species were collected across the various states. Collection rates ranged from one Bombus per week in Florida to over thirty per week in Utah and West Virginia. Bombus fervidus, B. bimaculatus, B. impatiens, B. pensylvanicus, and B. huntii were the five most abundant species within traps, comprising 86% of total captures. Species richness was consistent with published data suggesting that Bombus captures are representative of the expected community. However, some of the commonly trapped species (B. fervidus, B. pensylvanicus, and B. auricomus) are historically uncommon throughout their ranges. Future work will seek to understand which large-scale environmental features drive pollinator diversity and community composition.