Physiological responses underlying the timing of vernal activities in insects

Abstract

Temperate zone insect species have evolved three general strategies for synchronizing the end of hibernation with the return of favorable conditions. Recent eco-physiological studies of insect dormancy and development indicate that the prevailing concepts of the adaptations regulating hibernation and the resumption of spring activity, need revision. In particular, experimental evidence shows that despite implications in the term, dormancy is a dynamic state; the organism, by constantly monitoring the constantly-changing environmental parameters, is kept in phase with the seasons at its particular locality. Furthermore, the insect's ability to respond to environmental factors generally changes as the season progresses. Therefore, the construction of realistic predictive models of insect seasonality should be based on investigations of natural populations undergoing hibernation in the field, combined with ecologically and physiologically meaningful laboratory studies.