Assessing the Repellency of an Insecticide-Fungicide Combination to Bees Using Bioacoustics

Area of Science:

• Agronomy
• Ecology
• Entomology

Background:

• Soybean-bee interactions are vital for pollination and yield.
• Pesticide use during soybean flowering may harm bees, reducing pollination benefits.

Purpose of the Study:

• To investigate the impact of pesticide application timing and soybean flowering stage on bee foraging and soybean yield.
• To compare bee activity and yield between pesticide-treated and untreated soybean plots.

Main Methods:

• Field experiment in Ohio (2023-2024) with soybean plots treated with pyrethroid insecticide and fungicide.
• Monitoring bee activity using audio recorders and the buzzDetect machine learning tool.
• Assessing soybean defoliation and yield across different treatments and timings.

Main Results:

• Pesticide application did not affect overall bee activity, regardless of timing (mid-morning vs. mid-day).
• Bee activity was higher during the R3 (full bloom) stage than R5 (late bloom) and higher in mid-day than mid-morning.
• No significant differences in soybean defoliation or yield were observed among treatments.

Conclusions:

• Pesticide application timing and soybean growth stage influence bee foraging patterns.
• Current pesticide application strategies may not significantly disrupt bee activity or soybean yield.
• Findings can guide recommendations for minimizing bee exposure to pesticides during soybean flowering.