Effects of some pesticides on Bombus terrestris under laboratory conditions

Abstract

Pesticides have not only lethal effect on bees but they can also change their navigational behaviors. The bumblebees exposed to pesticides may not find their food and hive, and even their motor nervous system can acutely be affected. In this study, effects of some pesticides (abamectin, acetamiprid, deltamethrin, imidacloprid) on bumblebees were investigated. The bumblebee colonies were obtained from Koppert Biological Systems, Inc., Turkey. Six doses of each pesticide were tested on motor behaviors of some extremities of the bumblebees and bumblebees were fed on only 50% sucrose as a control group to compare with pesticide applications. Pesticides were applied to bees by feeding and spraying methods. Then, the situations of motor mobility of legs, antennae and proboscis extension of the bumblebees exposed to pesticides were scored. According to the results of the study, the pesticides used in the experiment had an impact on motor nervous system of the bumblebees, and the most effective pesticide was imidacloprid, followed by deltamethrin, acetamiprid, and abamectin, respectively. These results show that imidacloprid, all doses, demage basic motor coordination fundamental to locomotion and foraging and kill at label dose.