Yin, X., Department of Biological Systems Engineering, Washington State University, Pullman, WA, United States, College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China
Wang, S., Department of Biological Systems Engineering, Washington State University, Pullman, WA, United States
Tang, J., Department of Biological Systems Engineering, Washington State University, Pullman, WA, United States
Hansen, J.D., USDA-ARS Yakima Agricultural Research Laboratory, Wapato, WA, United States
Lurie, S., Department of Postharvest Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel, Department of Postharvest Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel

Levels of HSP70 protein of fifth-instar codling moth [Cydia pomonella (L.) (Lepidoptera: Tortricidae)] are determined after conditioning at 35°C for different times and also after recovery at 22°C. Protein samples from larvae conditioned for different times are separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis electrophoresis. Sub-lethal thermal conditioning at 35°C for 40 min, 2, 6 and 18 h induces new protein bands in the extracts from treated codling moth larvae. Immunodetection with an antibody to a heat-inducible HSP70 indicates a stronger reaction after 35°C for 2, 6 and 18 h than after 35°C for 40 min or control and, during the recovery period at 22°C, the level of heat shock protein decreases. Conditioning of fifth-instar codling moths at 35°C also induces thermotolerance in the insects and necessitates longer times at a lethal temperature to ensure mortality. Thermotolerance is correlated with the accumulation of heat inducible HSP70 protein. © 2006 The Authors.