Occurrence and Significance of Vitellogenins in Female Castes of Social Hymenoptera

A female specific protein is found in queens, workers, and gvnandromorphsof several species of social Hymenoptera. Possibly it is presentalso in experimentally produced diploid males, but it couldnot be found in normal haploid drones. A high tiler of the femalespecific protein (vitellogenin) is found in the hemolymph ofhoneybee queens during periods of oviposition and even duringperiods when no eggs are laid. A high titer is also observedin egg-laying workers of the honeybee and the stingless bees.Rates of synthesis of vitellogenin are negatively correlatedwith the concentration in the hemolymph. In nursing workersrates of vitellogenin synthesis are twice as high as in egg-layingworkers. In non-laying workers vitellogenin normally only occurs in thehemolymph of nursing workers; this period of nursing is moreextended in A. florea than in A. mellifica, a fact which maysignal a more primitive level of female caste differentiationin A. florea. Aspects of genetic, endocrine, and social regulationof vitellogenin synthesis are discussed.