Cold tolerance in diapausing and non‐diapausing stages of the flesh fly, Sarcophaga crassipalpis

Abstract

ABSTRACT. Supercooling points (SCP) and low temperature tolerance were determined for larval, pupal and adult stages of Sarcophaga crassipalpis Macquart (Diptera: Sarcophagidae). No stage tolerates tissue‐freezing. Ontogenetic changes in SCP profiles are similar for comparable developmental stages of diapause and non‐diapause groups. Feeding larvae have SCPs near ‐7°C which decrease to ‐11°C in the postfeeding wandering phase of the final larval instar. The lowest SCPs are recorded for pupae at ‐23°C. The capacity to survive at ‐17°C varies with age of the diapausing pupae: 10‐day‐old pupae are less cold tolerant than pupae that have been in diapause for 45–80 days. Although the SCP of non‐diapausing pupae is as low as in diapausing pupae, non‐diapausing pupae are extremely sensitive to low temperature exposure and do not survive to adult eclosion when exposed to ‐17°C for as little as 20 min. The use of hexane to break pupal diapause has no effect on SCPs or low temperature tolerance.