Evaluation of the effectiveness of microwave radiation on different developmental stages of Khapra beetle Trogoderma granarium Everts (Col.:Dermestidae)

The Khapra beetle is one of major pest of stored products, specially wheat and barley. The present research was conducted to study the applicability of microwave radiation at specified power rates and exposure times to control.
Each developmental stage was exposed to 2450MHZ at power levels of 300, 400 and 500W for 3 and 4 min. Experiments were arranged in completely randomized deign with 3 replications. After treatment, samples were kept under constant conditions in an incubator at 35±1 C and 70±5% R.H and 16D: 8L photoperiod. The most effective radiation to reduce the egg hatching rate, to induce mortalities in larvae, pupae and adults was the power rate of 500W and exposure time of 4 min. The order of sensitivity of different developmental stages was egg, last- instar larvae, adult, pupa and first-instar larvae.The result also revealed a direct relationship between exposure time at constant power led in increase in mortality of the insects. 1-2 days old eggs were more resistant than 0-1 and 2-3 days old eggs. A low power rate resulted decreasing oviposition rate and loss of tails in first-instar larvae .Based on the results the 500W and exposure time of 4 min. can be recommended for control of the Khapra beetle.