Effects on Honey Bees of Insecticides Applied to Snap Beans in Wisconsin: Chemical and Biotic Factors

Abstract

Studies were conducted to determine the role of snap beans as a food resource for honey bees (Apis mellifera L.), bee mortality resulting from pesticides, and the long-term effects on bees of such insecticide exposure. Aerial application of microencapsulated methyl parathion induced elevated levels of bee mortality and reduced total pollen collection rates, whereas treatment with acephate did not. Honey bees did not forage snap beans for pollen or nectar even under conditions of extreme resource dearth. Bee mortality following application of insecticides was caused by foraging either on blooming weeds in the field or among flowering plants within the spray-drift zone. Thus, such bee losses in snap beans could be avoided almost entirely through clean cultivation. High intercolony variability obscured possible differences in winter survival after exposure and in subsequent honey production.