Effect of Cold Temperature Treatments on the Mortality of Eggs and Feeding Larvae of the Oriental Fruit Moth

Abstract

Two cold storage treatments were evaluated against eggs, early instars, and late instars of the oriental fruit moth [Cydia molesta (Lepidoptera: Tortricidae)] a quarantine pest for Mexico of stone and pome fruit from the United States. In the first, `Delicious' apples (Malus domestica) were infested with these life stages and treated for 13 weeks in cold storage at 38 °F (3.3 °C) in replicated studies. In the second, the same life stages infesting `Delicious' apples were exposed to air temperatures slightly above freezing, 33.3 ± 0.7 °F (0.7 ± 0.4 °C), up to 7 weeks to simulate near commercial storage conditions. Weekly subsamples of the life stages were examined for survival. At 38 °F, complete mortality was obtained for eggs and early instars by the eighth week, and for late instars by the tenth week. At near freezing temperatures, eggs and early instars died by the fourth week, and late instars eliminated by the sixth week. This study demonstrated that the treatments were effective against the infesting life stages.