Effects of Permethrin on Mortality and Foraging Behavior of Honey Bees in Sweet Corn 1

Permethrin, a pyrethroid insecticide, was evaluated over a 3-year period (1979–1981) on sweet corn to determine its effects on honey bee mortality and field foraging behavior. Treatments were applied by helicopter between 5:30 and 7:30 a.m. at a rate of 0.22 kg (AI)/ha, repeated every 3 to 6 days for up to six applications per season. Permethrin did not cause abnormal bee kills; highest mortalities per colony averaged less than 70 dead bees per day. Up to 100 dead bees per colony was considered normal die-off. Permethrin repelled most honey bees from entering treated fields. Based on the results of these studies, permethrin can be used on sweet corn as a foliar spray without harm to honey bees, if applied at a time when bees are not foraging.