Backcrossing Africanized Honey Bee Queens to European Drones Reduces Colony Defensive Behavior

The defensive behavior of honey bee, Apis mellifera L., colonies of different genotypic composition was studied. Workers within colonies varied with respect to the proportion of their genotypes that were of African origin. Two components of defensive behavior were measured: the time it took for the first worker in a colony to respond and sting a moving leather patch, and the total number of stings deposited by workers in the patch during a 60-s interval following the first sting. Hybrid (F1) colonies were not different for either variable from feral-captured Africanized colonies. However, colonies of the two backcrossed generations had fewer stings in patches than Africanized colonies and did not differ from European colonies. Results suggest that the intense defensive behavior of Africanized bees is dominant over the less defensive behavior of the Europeans we tested. Results also suggest that it is possible to reduce the defensiveness of Africanized colonies to levels not different from those of European colonies after only two generations of crossing Africanized queens to European drones.