Modulation of honey bee thermoregulation by adrenergic compounds.

The effects of adrenergic compounds on the thermoregulation of resting honey bees were investigated using a non-traumatizing approach. Bees fed ad lib were treated orally and kept at an ambient temperature of 22 degrees C; the surface thoracic temperature was monitored by infrared thermography. Bees were treated with the adrenergic agonists epinephrine and ephedrine, and with the beta-blocking agent alprenolol. Low doses of adrenergic agonists had no significant effect on thermogenesis, but high doses caused a hypothermia. Alprenolol triggered a dose-dependent hypothermia that was reversed by low doses of epinephrine and ephedrine. Results are discussed with reference to the metabolic and neural adrenergic pathways that may be involved in bee thermoregulation.