Author
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Neven, Lisa |
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Rehfield-Ray, Linda |
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Obenland, David - Dave |
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Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/13/2006 Publication Date: 10/1/2006 Citation: Neven, L.G., Rehfield, L.M., Obenland, D.M. 2006. Confirmation and efficacy tests against codling moth and oriental fruit moth in peaches and nectarines using combination heat and controlled atmosphere treatments. J. Econ. Entomol. 99(5): 1610-1619. Interpretive Summary: Codling moth and oriental fruit moth are internal fruit feeding pests of quarantine concern in commercially grown peaches and nectarines in the United States of America. Current quarantine procedures involve either fumigation with methyl bromide or a system approach. Significant damage often occurs when fruit are fumigated with methyl bromide. An alternative, non-chemical quarantine treatment was desired by the conventional industry in California and organic industry in Washington. A combination heat treatment under low oxygen and elevated carbon dioxide environment was determined to be a viable non-chemical treatment for peaches and nectarines. Two treatments were developed using linear heating rates of 12 and 24°C/hr for 3 and 2.5 hr, respectively. It was determined by researchers at USDA, ARS, Wapato, Washington and USDA, ARS, Parlier, California, that the 4th instar of both species was the most tolerant infestive stage, and that both species were nearly equally tolerant to one another. Efficacy tests, treating 5,000 of the most tolerant stage with zero survivors, were performed on oriental fruit moth using both treatments. Confirmation tests, treating 30,000 of the most tolerant stage with zero survivors, were performed on codling moth using both treatments. It was also determined that both treatments did not significantly alter the fruit quality parameters that were evaluated to a degree that would have negatively influenced the marketability of the fruit. Positive benefits of treatment included a slower ripening of treated fruit and an inhibition of the loss of juiciness during storage in some cultivars. These treatments may be used as a replacement to methyl bromide fumigation for conventional fruit or as a new treatment for organic fruit contingent upon importing countries approval. Technical Abstract: Two high-temperature, forced air treatments under controlled atmosphere conditions, were developed for control of all life stages of codling moth and oriental fruit moth infesting peaches and nectarines. These treatments were used in efficacy and confirmation tests to kill over 5,000 4th instar oriental fruit moths and over 30,000 4th instar codling moths with zero survivors, respectively. The treatments consist of linear heating rates of either 12 or 24°C/h to a final chamber temperature under a 1% O2, 15% CO2, >90% RH atmosphere with air speed between 1.2 and 2.0 m/s. At a 12°C linear chamber heating rate treatmentit takes approximately 3 h to reach a final chamber temperature of 46°C. The average lowest core temperatures of the fruit reached 43.8°C within the last 30 min of the treatment. At a 24°C linear chamber heating rate, it takes approximately 2.5h to reach a final chamber temperature of 46°C. The average lowest core temperatures of the fruit reached 44.6°C for the last 15 min of the treatment. It was also determined that both treatments did not significantly alter the quality parameters that were evaluated to a degree that would have negatively influenced the marketability of the fruit. Positive benefits of treatment included a slower ripening of treated fruit and an inhibition of the loss of juiciness during storage in some cultivars. These treatments may be used as a replacement to methyl bromide fumigation for conventional fruit or as a new treatment for organic fruit contingent upon importing countries approval. |
