Toxicological evaluation of larval exposure to the mixture of the clothianidin neonicotinoid insecticide and the strobilurin pyraclostrobin fungicide on the development of Africanized Apis mellifera

Abstract

The decline of Apis mellifera bee colonies has become a worldwide concern and has been attributed to multiple stressors, such as the indiscriminate use of pesticides in growing areas. Most of the toxicological studies of pesticides evaluate isolated effects of each pesticide, however in the environment these substances are combined, which may increase the effects on bee colonies. The present study aims to evaluate the biological effects of continuous exposure of A. mellifera larvae to the Clothianidin neonicotinoid insecticide and to the Strobilurin Piracostrobina fungicide in isolation and in combination. Bioassays will be performed with larvae with two sublethal concentrations of each pesticide, the two being considered realistic, in other words, environmentally relevant. The evaluated parameters will be larval mortality, larval development progression, pupal morphology, emergence rate, and longevity of newly emerged bees. The results obtained will be analyzed statistically by pertinent methods. The present study will provide important data to understand the effect of the mixture of agrochemicals during the development of bees.