Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2001
Publication Date: 2/20/2002
Citation: JOHNSON, J.A., VAIL, P.V., BRANDL, D.G., TEBBETS, J.S., VALERO, K.A. INTEGRATION OF NON-CHEMICAL TREATMENTS FOR CONTROL OF POSTHARVEST PYRALID MOTHS (LEPIDOPTERA: PYRALIDAE) IN ALMONDS AND RAISINS. JOURNAL OF ECONOMIC ENTOMOLOGY. 2002. 95(1): 190-199.
Interpretive Summary: In California, where the annual production of dried fruits and nuts is over one million metric tons and is worth nearly $1.5 billion, costs due to insect-related product loss and control measures are substantial. Currently, these industries depend on fumigation with methyl bromide or phosphine for postharvest insect control. Processors use fumigants to disinfest large volumes of the incoming product during harvest, and to control infestations during storage. Because of regulatory restrictions and the development of resistence, the need for economical alternative systems that provide efficacious control and maintain product quality throughout processing, storage, and marketing is critical. At present, no single proposed non-chemical method is a suitable substitute for fumigation. This study demonstrated the efficacy of an integrated control method for postharvest almonds and raisins that combined initial disinfestation using controlled atmospheres (0.4% oxygen) with protective treatments of a microbial agent (Indianmeal moth granulosis virus), cold storage (10C) or maintenance levels of controlled atmosphere (5% oxygen). The initial disinfestation treatment was effective against navel orangeworm and raisin moth. All three protective treatments protected product from Indianmeal moth populations that were far higher than those found in commercial storage facilities. Overall product quality for all protective treatments for both raisins and almonds was maintained at levels acceptable by industry standards.
Technical Abstract: We propose a treatment strategy combining an initial disinfestation treatment with one of three protective treatments as an alternative for chemical fumigation of almonds and raisins for control of postharvest insect populations. Initial disinfestation treatments using low oxygen controlled atmosphere (0.4% oxygen) were designed to disinfest product of field populations of pyralid moths; navel orangeworm,Amyelois transitella (Walker) in almonds and raisin moth, Cadra figulilella (Gregson) in raisins. The protective treatments were cold storage (10C), controlled atmosphere (5% oxygen) storage, and application of the Indianmeal moth granulosis virus, and were designed to prevent establishment of Indianmeal moth, Plodia interpunctella (H¿bner). The initial disinfestation treatment was effective against laboratory populations of navel orangeworm and raisin moth. Efficacy of protective treatments was determined by exposure of commodities to laboratory Indianmeal moth populations, at levels far highe than those found in commercial storage facilities. All three protective treatments prevented development of damaging Indianmeal moth populations as measured by pheromone trap catches and evaluation of product samples. Quality analysis by commercial laboratories showed that overall product quality for all protective treatments was maintained at levels acceptable by industry standards.