Effect of an organic pesticide on mortality and learning in Africanized honey bees (Apis mellifera L.) in Brasil

Abstract

Seven experiments were conducted. First, the influence of the consumption of different concentrations of the organic pesticide Bioganic® on mortality was assessed at 11 different time intervals in Africanized honey bees (Apis mellifera L.) as was direct application of the pesticide to the abdomen. Results indicated that the pesticide was not lethal to bees regardless of concentration at any intervals tested whether consumed directly or applied to the abdomen. Second, the effects of different concentrations of the pesticide on Pavlovian conditioning and complex learning were examined in harnessed foragers. Results suggest that the pesticide affected learning; however, this conclusion may be erroneous because the bees would not feed on the pesticide, thus making it impossible to properly assess Pavlovian conditioning and complex learning. Consequently, the effect of the agrochemical on complex learning was examined in free flying bees trained to land on targets. The results of free flying experiments indicated that bees did not avoid a target associated with the smell of the pesticide but did avoid the target if they had to drink the pesticide.