Humidity and Insect Metabolism

ENTOMOLOGISTS have suggested that certain insects may show a greater rate of metabolism in dry air than in moist at the same temperature. They believe that such increased metabolism should cause a greater production of metabolic water, to compensate for evaporation from the insect's body, and maintain a constant ratio of water to dry matter at different atmospheric humidities. This increase in metabolic rate is assumed to occur in resting insects which are not moving actively. Buxton1 obtained results which indicated that, at 23° C, the mealworm used up its reserves more rapidly in dry air than in moist, and kept the ratio of water to dry matter constant. As the body composition of mealworms is so variable, and as these results were obtained from rather small numbers, it appeared advisable to make further experiments before finally accepting a conclusion of such general physiological importance.