Evaluation of the synergistic effect insecticide fipronil and imidacloprid on mortality in native bees Melipona scutellaris

Abstract

The bees are essential for the environment because they are responsible for pollination of more than 70% of agricultural crops in the world. In Brazil there are six families of bees, Apidae family is the most numerous. Among the representatives of this family is the species Melipona scutellaris, popularly known as "uruçu" or "uruçu do nordeste". However, in the last 50 years there has been an increase in food production due to the intensification of agriculture, the use of fertilizers and pesticides, and irrigation. The Brazil has emerged as the greater consumer of pesticides in the world. The bees are not the target of insecticides, but they are highly vulnerable to contamination. Among the various existing insecticides, two has been showing up: fipronil and imidacloprid. The first block chloride channels receptor by acting on the gamma-aminobutyric acid (GABA) and the second acts as agonists of acetylcholine receptor. These insecticides may be used one after the other and so bees may be contaminated with both molecules. The simultaneous presence of more than one product leads to interactions between substances that can drastically change the nature and importance of the effects observed. Therefore, the aim of this work is to verify the effect of fipronil and imidacloprid alone and synergistically, on the stingless bee Melipona scutellaris. (AU)