Energy and lipid metabolism during direct and diapause development in a pierid butterfly

Diapause is a fundamental component of the life-cycle in the majority of insects living in environments characterized by strong seasonality. The present study addresses poorly understood associations and trade-offs between endogenous diapause duration, thermal sensitivity of development, energetic cost of development and cold tolerance. Diapause intensity, metabolic rate trajectories and lipid profiles of directly developing and diapausing animals were studied using pupae and adults of Pieris napi butterflies from a population for which endogenous diapause is well studied. Endogenous diapause was terminated after 3 months and termination required chilling. Metabolic and postdiapause development rates increased with diapause duration, while the metabolic cost of postdiapause development decreased, indicating that once diapause is terminated development proceeds at a low rate even at low temperature. Diapausing pupae had larger lipid stores than the directly developing pupae and lipids co...