Effect of the queen, brood and worker caste on haemolymph vitellogenin titre in Camponotus festinatus workers

Haemolymph concentration of vitellogenin and ovary development have been examined in Camponotus festinatus workers under inhibited (queenright) and uninhibited (queenless) conditions, in order to determine which social factors may affect worker oögenesis. While most queeright workers had very low vitellogenin titres, queenless workers maintained either in the presence or absence of pupae showed increasing vitellogenin titres. Mean vitellogenin concentration in 7-week-old queenless soldiers and 10-week-old queenless minor workers were 15-fold higher than those found in queenright workers of the same age. Larvae had an inhibitory effect on the haemolymph vitellogenin titres of workers, particularly of minor workers. Soldiers in the presence of minor workers showed significantly higher vitellogenin titres during early adult life. In spite of the accumulation of vitellogenin in the haemolymph of queenless workers, even far above the levels detected in some queens, oöcyte development did not occur in the majority of these animals.