EVALUATION OF THE REPELLENT EFFECTS OF A NEEM INSECTICIDE ON FORAGING HONEY-BEES AND OTHER POLLINATORS

A standardized, oil-free neem (Azadirachta indica A. Juss) seed extract (NSE) was tested for repellency to honey bees using a feeding-dish choice bioassay, and to honey bees and other pollinators in field applications on blooming canola. Foraging honey bee workers were able to discriminate between untainted sugar syrup and syrup containing formulated NSE at concentrations as low as 0.1 ppm azadirachtin, the principal active ingredient of NSE. However there were no significant differences in the numbers of foraging bees collected in neem-treated, solvent-treated, or untreated canola plots. Other pollinator species present were similarly unaffected. Our results suggest that honey bees may be successfully utilized in blooming crops that have been treated with doses of NSE sufficient to control phytophagous insect pests. The results of this study also suggest that using feeding-dish bioassays to screen potential repellent compounds, although demonstrating the ability of honey bees to detect compounds, may not yield similar results in the field.