|Hansen, James D|
Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2003
Publication Date: 2/3/2004
Citation: Wang, S., Yin, X., Tang, J., Hansen, J.D. 2004. Thermal resistance of different life stages of codling moth (Lepidoptera:Tortricidae). Journal of Stored Products Research. 40:565-574. Interpretive Summary: The codling moth is a quarantine pest for certain countries, including Japan. Heat treatments of fresh fruits and vegetables are rapidly becoming the preferred procedure for disinfesting quarantine pests. For a heat treatrment to be accepted by Japan, specific requirements must be met. One is identifying the most resistant life stage. This manuscript describes the methods used to determine the most heat resistant life stage of the codling moth and identifies it as the fifth instar. With this information, efficacy tests against the codling moth can now be done using heat treatments.
Technical Abstract: Phytosanitation regulations in several international markets require postharvest treatments to control codling moth, Cydia pomonella (L.) (Lepidoptera:Tortricidae), in various commodities. Thermal treatments are gaining acceptance to replace chemical fumigation. Determining the most thermal tolerant life-stage is essential in the development of effective postharvest insect control protocols based on thermal energy. A heating block system was used to evaluate relative heat resistance of five different life stages of codling moth: white-ring eggs, black head eggs, third-instar, fifth-instar, and diapausing larvae, at a heating rate of 15 degrees C per minute. The fifth-instar was the most heat resistant life stage in the tested temperature range of 50 to 52 degrees C except for diapauses. Thermal death kinetic data fo diapausing fifth-instar larvae were determined and also compared with published TDT curve of non-diapausing larvae using the same heating block system. The time required to achieve 100% mortality of 600 insects for both types of larvae was the same and decreased with temperature. But under sub-lethal heat treatment conditions, dispausing larvae appeared to be more heat resistant than non-diapausing larvae.