Wild bees and wasps (Hymenoptera) visiting soybean (Fabaceae) flowers in eastern Canada

Abstract

Although insect pollination has been shown to enhance yields of soybean, Glycine max (Linnaeus) Merrill (Fabaceae), the lingering misconception among growers that soybean does not benefit from insect pollination hinders the adoption of pollinator-friendly practices. As such, identifying the wild pollinators visiting soybean flowers can help raise awareness of their importance in soybean production. We surveyed wild bees and wasps visiting soybean flowers and carrying soybean pollen in an extensive field crop region of southeastern Canada (Ontario and Quebec). Insects were hand-netted from 19 soybean fields while they actively foraged on soybean flowers, and their corbicular or scopal loads and body surfaces were screened for soybean pollen. A total of 81 insects (77 wild bees and four wasps), representing 18 bee and four wasp species, were collected. The majority (91.4%) carried soybean pollen, indicating a potential role in soybean pollination. Generalist bumble bees and ground-nesting bees were the most common, suggesting that management practices that support these two groups are likely to be particularly relevant for growers in Canada.