Project Number: 2080-21000-019-33-I
Project Type: Interagency Reimbursable Agreement
Start Date: Dec 15, 2020
End Date: Jun 14, 2022
1. Develop methods for quantifying pesticide drift on farms. 2. Quantify pesticide drift into field margins adjacent to highbush blueberry fields. 3. Document wild bees present in field margins adjacent to highbush blueberry fields. 4. Quantify pesticide exposure for alkali bees adjacent to alfalfa seed production.
1. Develop methods for quantifying pesticide drift on farms: Silicone bands are used to quantify pesticide drift. However, degradation rates of insecticides on bands have not been established. Therefore, we dipped 42 bands in field application concentrations of five commonly applied insecticides: phosmet, acetamiprid, spinetoram, malathion, and imidacloprid. Bands were then attached to poles in an open field. Immediately after placement, six bands were randomly selected and collected for a 0 day replicate. Collected bands were wrapped in aluminum foil and stored at -20°C. These collection methods were continued at days: 1, 3, 7, 14, 21, and 28. Bands will be sent to the Cornell Chemical Ecology Core Facility (CCECF) and insecticides will be quantified via a modified QuECheRS extraction protocol and analyzed on an LC-MS/MS system. 2. Quantify pesticide drift into field margins adjacent to highbush blueberry fields: Quantification of pesticides in field margins will allow us to estimate bee exposure at resources (weeds or wildflower plantings). In July and August of 2020 (pre-harvest and harvest), silicone bands were placed at set distances away from blueberry bushes at 15 conventional farms in Michigan. Bands were secured to poles and placed at vegetation height along two transects perpendicular to the blueberry planting (0m, 2m, 4m, 8m, 16m, 24m, and 32m). Bands were left out between 7-21 days (avg. 12.87 +/- 1.56 S.E.), and for at least one pesticide application. Bands were then collected as above and will be sent to CCECF and screened for 261 pesticides. 3. Document wild bees present in field margins adjacent to highbush blueberry fields: Wild bees use floral resources available in the field margins on blueberry farms. However, these resources are in close proximity to pesticide applications. This could pose a risk to wild bees, particularly when higher toxicity products are used post-bloom. Flowers and soils collected from field margins, as well pollen collected by bumble bees are currently being quantified for residues at the CCECF. However, wild bees collected in field margins at the same time have not yet been identified to species, which would help inform which species are likely to be impacted by pesticide drift. Therefore, collected bees will be sent to a bee taxonomic expert, Dr. Jason Gibbs (Univ. of Manitoba), for identification. 4. Quantify pesticide exposure for alkali bees adjacent to alfalfa seed production: Alkali bees, Nomia melanderi, are native solitary ground nesting bees that are important managed pollinators for alfalfa seed production. Growers in the Touchet valley of WA have been managing alkali bee beds (aggregations of nesting bees) for pollination for over fifty years. Alkali bees are incredibly efficient pollinators of alfalfa and large aggregations provide demonstrable contributions to crop production. However, bee beds are in close proximity to agricultural fields, and therefore could put bees at risk of pesticide exposure. Therefore, we will take soil cores from bee bees to quantify pesticide residues at the CCECF, and use these results to develop management practices to limit exposure from runoff or drift.