Can Commodity Crop Weed Management Practices Enhance Bee Abundance Diversity And Health On Agricultural Land?

Relative to tilled agricultural fields, those utilizing no-till farming practices may provide relatively undisturbed nesting habitat for wild bees, which construct their nests within centimeters of the soil surface. Moreover, the early-spring flowering period of winter annual weeds, which are often used as a cover cropping method in no-till systems, coincides with the onset of honey bee foraging activity following winter dormancy, as well as the initiation of the nesting and reproductive period of early spring ground-dwelling bees. In the current project, we investigate how low-impact no-till farming and corresponding weed management practices that alter the abundance of flowering winter annual weeds could impact honey bee colonies and ground-nesting bees. In aim 1, we document the relative abundance of bee visitors, particularly those of the ground-nesting genera Andrena and Colletes, on weedy winter annual flowers. In aim 2, we determine the suitability of crop fields for nest use by ground-nesting bees. In aim 3, we experimentally test whether spring herbicide applications for soy and corn cause mortality in ground-nesting bees. In aim 4, we determine how winter annual forage availability influences honey bee colony productivity and growth, as well as individual worker immune function, early in the spring. This project has the potential to influence best management crop practices, to evaluate how interacting stressors impact pollinator health, and to provide information for outreach and educational programming.