Effect of activity on the haemolymph sugar titres in honey bees
Janko Božič; Joseph Woodring;
Dancing forager honey bees had significantly lower haemolymph trehalose titres than bees following dancers or resting bees at the same time of day. Followers and dancers had a higher glucose titre than resting bees, probably because of elevated activity. Fructose titres were higher in dancers than followers, probably because dancers had recently collected nectar. During absconding, almost all of the haemolymph trehalose disappeared. This possibly was a result of the high energy demands required for long periods of hovering flight in front of the hive that are characteristic of absconding. Absconding and swarming bees may come to rest in the immediate vicinity of the hive to regenerate haemolymph trehalose titres. The trehalose titre was restored within an hour after absconding. Intense shaking and agitation of small groups of bees in a cage could not duplicate the very high level of activity during absconding. Shaking resulted in reduced glycogen levels in the flight muscles and an increased haemolymph fructose titre, but no decrease in trehalose titre. On the first clear day following several rainy days, foragers were more excited, as noted by more vigorous running about, and they had higher glucose titres and lower trehalose titres than after a sunny day. Increased foraging probably led to increased ingestion of food, which in turn lead to increased glucose titres. Bees sampled in the autumn had higher trehalose and lower glucose titres than bees sampled in the spring, and this finding may be due to more intense foraging activity in the spring.