Calorimetric investigations on activity states and development of holometabolous insects

Holometabolous insects are an extraordinarily species-rich animal taxon, ch aracterized by a clear distinction between larvae, pupae and adults in thei r lifecycles. From a calorimetrist's point of view, they are interesting st udy objects because larvae and adults often have very different lifestyles. Some common patterns of the time course of metabolic rates are observed du ring calorimetric investigations. Larvae have high metabolic rates after ha tching from the egg, up to 160 mW/g in the wax moth Galleria mellonella. Pr ior to pupation, metabolism is strongly reduced. During metamorphosis, the pupal instars typically exhibit a U-shaped pattern of heat production. Inse ct adults have low resting metabolic rates, close to the pupal metabolism. Metabolic rates of Eying insects are up to 50 times higher than resting met abolism. (C) 2000 Elsevier Science B.V. All rights reserved.