Bumblebee Thermal Tolerance

Maximal critical thermal tolerance (CTmax) of castes and larvae of a bumblebee (Bombus impatiens) and the effect of environmental temperature on the colony metabolic rate and nest temperature. Larval CTmax is significantly lower than the CTmax of adult castes. Whole-colony thermoregulation is energetically costly at high and low temperatures. Colonies experiencing 30°C and below successfully thermoregulate nest temperature. Above 30°C, nest temperature cannot be regulated via colonial thermoregulation.