Caste determination is a sequential process: effect of larval age at grafting on ovariole number, hind leg size and cephalic volatiles in the honey bee (Apis mellifera carnica)

Artificial queen rearing with worker larvae grafted at different developmen tal stages resulted in gradual effects on ovary size (number of ovarioles p er ovary), as well as hind leg and wax gland structures in adults. A signif icant decrease in ovariole number was observed when third instar larvae wer e grafted. Basitarsus shape was affected when fourth instar larvae were gra fted. Queen-worker intermediates developed when early-fifth instar worker l arvae were transferred. As newly emerged adults, spectra of cephalic volati les of queens and workers are still very similar, and do not yet exhibit th e caste-specific elements of the mandibular glands. At one day after emerge nce, most of the dominant compounds in these spectra are represented at hig her levels in workers.