Response of Codling Moth (Lepidoptera: Tortricidae) to High Temperature, a Potential Quarantine Treatment for Exported Commodities

Abstract

Response of codling moth, Cydia pomonella (L.). eggs and first through fifth instars to each 1.0°C increase in temperature from 45.0 to 51.0°C was directly related to a lower LT50 and less time to cause 100% mortality for each life stage. An increase in temperature caused a decrease in the minimum exposure time needed to prevent adult emergence from treated immatures. Exposure of either the female or male to 44.0 or 45.0°C for 20 min in the fourth or fifth instar resulted in fewer eggs laid per female and lower egg viability than in the unexposed controls. Exposure of the male had a greater effect on fecundity than exposure of the female. Viable eggs were laid by pairs in which either the female or male was exposed to 45.0°C for 20 min in the fourth instar. No histological abnormalities were found in the testes of adult male codling moths that had been exposed to 46.0°C for 20 min in the fifth instar.