The effect of sugars and juvenile hormone on the differentiation of the female honeybee larvae (Apis mellifera L.) to queens.

The effect of the addition of sugars to diet and topical application of Juvenile Hormone on the di-ferentiation of undetermined female larvae to queens was examined. The basic diet was Worker Jelly (WJ) with 4% glucose (G) and 4% fructose (F) added. Larvae reared on this diet emerged as workers only. Larvae reared on WJ with 8% G and 8% F differentiated to adult intermediates or workers. High amounts of G and F (16 to 20%) caused the larvae to develop to adult queens, intermediates and workers. When 2- to 3-day-old larvae were reared on WJ (with 4% of G and F, each) and topically treated with 10 μg Juvenile Hormone (JH) per larva, they differentiated and emerged only as queens. Lower amounts of JH (1 μq per larva) caused differentiation of larvae to 50% queens and 50% workers. The possible mode of action of sugars and Juvenile Hormone is discussed.