Fig. 1. Course of air temperatures in the field (A) and the temperature protocol used for laboratory acclimation (B) of Pyrrhocoris apterus. The adult insects were sampled on 23 October and 27 December in the field. Laboratory adults were maintained under short days conditions (12 h:12 h, L:D). Their physiological state was considered as the initial state when they reached age of 4 weeks. Three different treatments were then applied: progression of diapause, desiccation, and cold acclimation (see text for detailed descriptions).