Juvenile Hormone - Juvenile Hormones in Honey Bees

Juvenile Hormones in Honey Bees

There is a complex interaction between JH, the hormone ecdysone and vitellogenin. In the development stage, as long as there is enough JH, the ecdysone promotes larva-to-larva molts. With lower amounts of JH, ecdysone promotes pupation. Complete absence of JH results in formation of the adult. In adult honey bees, JH and Vitellogenin titers in general show an inverse pattern.

JH titers in worker honey bees progressively increase through the first 15 or so days of the worker's life before the onset of foraging. During the first 15 days, workers perform tasks inside the hive, such as nursing larvae, constructing comb, and cleaning cells. JH titers peak around day 15; workers this age guard, remove dead bees from the colony, and fan at the colony entrance to cool the nest. Aggressiveness of guard bees is correlated with their blood JH levels. Even though guards have high JH levels, their ovaries are relatively undeveloped. Although, JH does not activate foraging. Rather it is involved in controlling the pace at which bees develop into foragers.

Vitellogenin titers are high at the beginning of adult life and slowly decrease.

JH has been known to be involved in the queen-worker caste differentiation during the larval stage. The unique negative relationship between JH and Vitellogenin may be important to the understanding of queen longevity.

See also Bee learning and communication