BACKCROSSING AFRICANIZED HONEY-BEE QUEENS TO EUROPEAN DRONES REDUCES COLONY DEFENSIVE BEHAVIOR

The defensive behavior of honey bee, Apis mellifera L., colonies of di fferent genotypic composition was studied. Workers within colonies var ied with respect to the proportion of their genotypes that were of Afr ican origin. Two components of defensive behavior were measured: the t ime it took for the first worker in a colony to respond and sting a mo ving leather patch, and the total number of stings deposited by worker s in the patch during a 60-s interval following the first sting. Hybri d (F1) colonies were not different for either variable from feral-capt ured Africanized colonies. However, colonies of the two backcrossed ge nerations had fewer stings in patches than Africanized colonies and di d not differ from European colonies. Results suggest that the intense defensive behavior of Africanized bees is dominant over the less defen sive behavior of the Europeans we tested. Results also suggest that it is possible to reduce the defensiveness of Africanized colonies to le vels not different from those of European colonies after only two gene rations of crossing Africanized queens to European drones.