The effects of sublethal exposure to diazinon, carbaryl and resmethrin on longevity and foraging in Apis mellifera L.

Abstract

Topical, sublethal applications of three insecticides, diazinon, carbaryl and resmethrin, were given to worker honey bees (Apis mellifera L.) of two age groups, 0 and 14 days. For newly emerged workers, carbaryl was the most hazardous in sublethal amounts, adversely affecting both longevity and foraging age. Resmethrin was intermediate in effect, and diazinon the least hazardous. The is different from mortality studies in which the effects of carbaryl and diazinon were similar, and resmethrin the most toxic. For 14-day-old workers, there were only two statistically significant differences affecting foraging in the sublethal studies, and these were not conclusive. However, in mortality studies carbaryl was the least toxic, diazinon intermediate and resmethrin the most toxic pesticide. Newly emerged worker honey bees were more sensitive to pesticide exposure, in both acute and sublethal effects, than older workers. In order to evaluate pesticide hazards to the honey bee, both laboratory and field tests should be used. A field bioassay involving sublethal exposure effects on longevity and foraging may be useful in this regard.