Print PageLittle baseline data exist regarding the role of wild, primarily native, non-Apis bees in pollinating crops through the growing season in the mid-Atlantic United States. Honey bees are generally assumed to provide the majority of crop pollination, with the value of pollination provided by non-Apis bees estimated at between one half and one sixth the value of honey bees, though many non-Apis bees are known to be more effective in pollinating some crops. In this study, the first to document wild bees visiting crop flowers throughout the growing season, non-Apis medium and bumble bees provided the majority of crop pollination—measured by visitation—for several economically important entomophilous crops in Virginia (apple, blueberry, caneberry, and cucurbits). Diversity of bees was as high within as across crops, suggesting that diverse bee populations may be helping to stabilize pollination service.
Results/Conclusions
Wild bees made up between 68% (in caneberries) and 83% (in cucurbits) of bees observed visiting crop flowers. Though a few bee species were especially abundant in each crop, between 43 and 59 species of non-Apis bees visited flowers in each crop system (105 species overall on crop flowers). There was low correspondence between bee communities across or within crops (“within crop” Jaccard similarity indices for richness ranged from 0.12–0.28). This tremendous diversity of bees suggests that non-Apis bees are also providing stability to pollination services, ensuring pollination if one or more species declines over time or space.
