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

A standardized, oil-free neem (Azadirachta indica A. Juss) seed extrac t (NSE) was tested for repellency to honey bees using a feeding-dish c hoice bioassay, and to honey bees and other pollinators in field appli cations on blooming canola. Foraging honey bee workers were able to di scriminate between untainted sugar syrup and syrup containing formulat ed NSE at concentrations as low as 0.1 ppm azadirachtin, the principal active ingredient of NSE. However there were no significant differenc es in the numbers of foraging bees collected in neem-treated, solvent- treated, or untreated canola plots. Other pollinator species present w ere similarly unaffected. Our results suggest that honey bees may be s uccessfully utilized in blooming crops that have been treated with dos es of NSE sufficient to control phytophagous insect pests. The results of this study also suggest that using feeding-dish bioassays to scree n potential repellent compounds, although demonstrating the ability of honey bees to detect compounds, may not yield similar results in the field.