D3063: The effects of RoundUp on wild ground-nesting bees: A field study approach

This project focuses on wild, spring-active native bee species primarily within the Andrena and Colletes genera. We 1) located and marked pairs of active bee nest aggregations within central Kentucky parks, 2) treated one nest aggregation in each pair with RoundUp and left the other aggregation as a control, 3) and excavated the aggregation areas to collect bees from within the nests to assess the impacts of the RoundUp treatment. In each round of data collection (over 3 consecutive years), we timed our excavations to evaluate different impacts of the RoundUp treatment. In Round 1, we excavated overwintered adults that were treated as developing larvae the previous year to assess the effects on adult weight and body size. In Round 2, we excavated bees beginning at two weeks post-RoundUp treatment and attempted to rear the excavated larvae in the lab to monitor survival. In Round 3, we excavated bee larvae beginning at 2 weeks post-RoundUp treatment to assess the effects of the RoundUp treatment on larval weight and size. We detected no significant effects of the RoundUp treatment in any round of the experiment on survival, weight, body size, or number of bees recovered from plots. We recovered several species of adult bees in Round 1 from the genera Andrena, Colletes, Lasioglossum, Nomada, and Halictus. We are currently identifying the adult bees from Round 1 to species using morphological keys and confirming these identifications and identifying larvae from Round 3 using DNA barcoding so that we can assess species-specific responses.