Integration of Nonchemical Treatments for Control of Postharvest Pyralid Moths (Lepidoptera: Pyralidae) in Almonds and Raisins

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% O2) 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 (10°C), controlled atmosphere (5% O2) storage, and application of the Indianmeal moth granulosis virus, and were designed to prevent establishment of Indianmeal moth, Plodia interpunctella (Hubner). 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 higher 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.