THE EFFECT OF MICROWAVE RADIATION WITH COLD STORAGE ON THE MORTALITY OF INDIAN MEAL MOTH (PLODIA INTERPUNCTELLA HUB.) EGGS

Due to hazardous effect of chemical insecticides treatment, the search for new, safe and readily available control techniques as alternative tools has received special attention during recent years. According to these criteria, the effect of microwave radiation with cold storage on different age groups of Indian meal moth eggs was investigated. The eggs were exposed to (2450 MHZ) at power levels of 100, 300 and 500W with 2, 4, 6, 8 and 10 min exposure duration. After treatment, the samples were kept under cold storage conditions (4±1°C) for 24 and 48h. Upon termination of cold storage period, the samples were placed under rearing conditions (27 ± 1°C; 65 ± 5% r. h.). Mortality rate had direct relation with microwave radiation power and exposure time. Moreover after 24 and 48 h cold storage, 100% mortality was achieved. The results showed that the maximum mortality rates (90.0 and 85.5%) were achieved for 1 and 2 day old eggs after 48 h cold storage duration respectively. However, in the case of 1 and 2 day old eggs, 24 h cold storage treatment was sufficient to achieve the highest rate of mortality (90.8 and 86.82%), respectively. Thus, 1 and 2 day old eggs were more tolerant than the other age groups under similar conditions of stress. It can be concluded that due to low rate of embryonic development within the first 2 days of incubation, the mortality rate of younger eggs could be significantly less than older cohorts.