Estimating the contribution of laying workers to population fitness in African honeybees (Apis mellifera) with molecular markers

Introduction Reproductive hierarchies are typical for insect societies. In the socially most advanced species, a queen dominates her daughter workers which help to raise the queen's offspring. Reproductive division of labour is particularly strict in honeybee colonies, Apis mellifera. The queen is the only reproducing female and the workers actively eliminate the few eggs which are occasionally laid by other workers, a process which has been coined "policing" (Ratnieks and Visscher, 1989). Queens, however, are not immortal. After loss of the queen, the honeybee colony usually rears an emergency queen from the young female larvae in the colony. In some Insectes soc. 45 (1998) 277 -- 287 0020-1812/98/030277-11 $ 1.50+0.20/0 Birkhuser Verlag, Basel, 1998 Insectes Sociaux Research article * Author for correspondence. cases however emergency rearing may fail and the colonies become hopelessly queenless, a situation which typically occurs in the case of queen loss after swarming. There i