GLUCOSE-UTILIZATION DURING FLIGHT OF HONEYBEE (APIS-MELLIFERA) WORKERS, DRONES AND QUEENS

Glucose utilization by honeybee workers, drones and queens (Apis mellifera L.) during tethered flight in a roundabout was measured by loss of [C-14]glucose. Glucose levels in the haemolymph of drones and workers increased rapidly when the bees fed on [C-14]glucose after an exhaustive flight. These levels were always higher in workers than in drones. Labelled glucose was incorporated into trehalose within 2 min of feeding. Flight speed was positively correlated with food concentration (1-4 molar glucose) for workers and drones, and the speed attained by queens was similar to that of workers. Only the speed of drones was temperature dependent and was significantly higher than that of workers and queens. Independent of glucose concentration, workers require more sugar per metre flown and gram body weight, and per gram thorax weight, than the much heavier drones and queens. Queens have the most economical flight.