Interactions between territorial soldier beetles (Chauliognathus basalis) and bees visiting sunflowers (Helianthus petiolaris)

Sunflowers are an important floral resource for insects on the plains of Colorado. A territorial soldier beetle, Chauliognathus basalis, often attempts to exclude other insects, including bees, from inflorescences it occupies. To understand the consequences of these interactions on bee visitation, I manipulated beetle presence on sunflower blooms in an outdoor garden and monitored bee visitation. After comparing paired 10 minute observations on 150 flowers, I found the effect of beetle presence on bee visitation varied across species. In areas with high soldier beetle abundance, they may play a role in shaping the bee community by limiting access to floral resources for some bees.