Heterosis in the Honey Bee as Shown by Morphological Characters in Inbred and Hybrid Bees

Abstract

Inbred queens from eight lines representing several races of honey bees (Apis mellifera L.) were mated (artificially inseminated) to drones of the same line and also to another line, so that inbred and hybrid worker offspring were produced simultaneously from each mother queen. By the use of genetic markers the two types of offspring were identifiable. Small but highly significant differences between lines were found in the characteristics length, wing width, cubital index, number of wing hooks, tongue length, and antenna lengths. The hybrid bees were usually larger than their inbred sisters. This difference in size suggests that hybrid vigor is present in honey bees. Uncontrollable feeding variability between colonies apparently accounted for significant differences in some samples.