Occurrence and significance of vitellogenins in female castes of social Hymenoptera

A female specific protein is found in queens, workers, and gvnandromorphs of several species of social Hymenoptera. Possibly it is present also in experimentally produced diploid males, but it could not be found in normal haploid drones. A high tiler of the female specific protein (vitellogenin)is found in the hemolymph of honeybee queens during periods of oviposition and even during periods when no eggs are laid. A high titer is also observed in egg-laying workers of the honeybee and the stingless bees. Rates of synthesis of vitellogenin are negatively correlated with the concentration in the hemolymph. In nursing workers rates of vitellogenin synthesis are twice as high as in egg-laying workers. In non-laying workers vitellogenin normally only occurs in the hemolymph of nursing workers; this period of nursing is more extended in A. florea than in A. mellifica, a fact which may signal a more primitive level of female caste differentiation in A. florea. Aspects of genetic, endocrine, and social regulation of vitellogenin synthesis are discussed.