Maternal Effects on the Hygienic Behavior of Russian x Ontario Hybrid Honeybees (Apis mellifera L.)

Abstract

Strains and hybrids of Russian and Ontario honeybees (Apis mellifera L.) were evaluated for hygienic behavior at both colony and individual levels. The objectives were to determine phenotypic and genotypic variability and to study the inheritance of this behavior. At the colony level, Russian bees uncapped and removed significantly more freeze-killed brood than Ontario bees. The most hygienic Russian colonies and the least hygienic Ontario colonies were selected to perform reciprocal crosses between the strains. Bees from the hybrid colonies as well as from the parental colonies were tagged and introduced into observation hives, where hygienic behavior was directly observed on a piece of frozen brood comb. Russian and hybrid bees of Russian mother had the highest percentages of workers uncapping cells and removing brood. Conversely, Ontario and hybrid bees of Ontario mother had the lowest percentages of individuals for these variables. Differences were also observed among the 4 genotypes for their degree of specialization on hygienic tasks. Russian and hybrid bees of Russian mother showed a significantly higher uncapping frequency per individual than Ontario and hybrid bees of Ontario mother. These results demonstrate phenotypic and genotypic variability for hygienic behavior and are suggestive of maternal effects in the inheritance of hygienic traits.