Effect of low temperature storage on survival and reproduction of Indianmeal moth (Lepidoptera: Pyralidae)

Low temperature storage is one component of an integrated control program suggested as an alternative to methyl bromide fumigation for Indianmeal moth, Plodia interpunctella (Hübner), in postharvest dried fruits and nuts. Long-term exposure to 10 °C lengthened the life of adults; 50% mortality was reached after 49 days of exposure, almost four times the average adult lifespan of 13 days at 27 °C. Adult mortality reached 90% after 70 days of exposure. Exposure to 10 °C for greater than 25 days reduced egg production by more than half and reduced the number of viable eggs by nearly 90%. Eggs were most susceptible to 10 °C; the exposure time estimated to obtain 95% egg mortality was 11.6 days. From these data this it was estimated that clean product that has been under storage at 10 °C and undisturbed for at least 4 weeks should be relatively free of Indianmeal moth.