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Abstract
Codling moth [Cydia pomonella (Lepidoptera: Tortricidae)], found in exported apples (Malus sylvestris), can disrupt international markets. Cold storage at 1.1 °C was examined for possible control of three physiological larval states in ‘Fuji’ apples: diapausing (overwintering), diapause-destined, and nondiapausing. All nondiapausing larvae were dead within 12 weeks, diapaused-destined larvae were controlled by the seventh week, yet more than half of the original populations of diapausing larvae were still alive after 11 weeks. Because the diapaused-destined larvae were younger than the nondiapausing larvae, they may have been more susceptible to cold. Because larvae normally diapause outside the fruit, cold storage would not be applicable for controlling larvae in this state.
Taiwan is the third largest importer of U.S. fresh apples (Taipei Times, 2005). The apples are primarily from Washington and California (Fruit Growers News, 2002), with ‘Fuji’ as the predominant cultivar comprising 80% of those from Washington (Jimenez, 2004). After over 25 years of apple exports to Taiwan, live codling moth larvae were found for the first time in 2002, leading to a temporary ban on U.S. apples (Fruit Growers News, 2002). To resume exports, the United States agreed to increase the numbers of apples inspected and, if live codling moth larvae were found in three consignments, all apple imports from the United States would stop (Taipei Times, 2005).
The systems approach (SA) is being expanded to meet these increasingly severe phytosanitary regulations for apples. The SA involves the cumulative effect of commercial operations to reduce the risk of possible pest infestation followed with validation by intense inspection. One area that can be exploited is the cold storage component. Cold storage is already used against the apple maggot [Rhagoletis pomonella (Diptera: Tephritidae)] (Hallman, 2004) and the oriental fruit moth [Cydia molesta (Lepidoptera: Tortricidae)] (Hansen, 2002) for apples exported to Mexico. A better understanding of the impact of cold storage on codling moth larvae would strengthen this component and improve the overall use of the SA.
Cold storage (55 d at 2.2 °C) for control of codling moth eggs is a component of the current quarantine treatment against codling moth for apples exported to Japan (Hansen et al., 2000). Thus, 1.1 °C, the temperature ‘Fuji’ apples are frequently stored, may also...