Paternal effects on the defensive behavior of honeybees.

The defensive behavior of 52 hybrid honeybee (Apis mellifera L.) colonies from four sets of crosses was studied and compared with that of European and Africanized bee colonies. Colonies containing F(1) hybrid workers were obtained through reciprocal crosses between European and Africanized bees. The total number of stings deposited by workers in a moving leather patch in 1 min was recorded. In each of the four sets of crosses, bees from hybrid colonies of Africanized paternity left more stings in leather patches than bees from hybrid colonies of European paternity. Results strongly suggest paternal effects of African origin increasing the defensive behavior of hybrid colonies. Although some degree of dominance was observed for high-defensive behavior in one of the four sets of crosses involving European paternity, most of the dominance effects reported in the literature appear to be the result of paternal effects. Several hypotheses to explain this phenomenon, as well as the implications of these effects on the fitness and breeding of honeybees are discussed.