The Influence of temperature and Microwave Radiation on The Lesser Grain Borer Rhyzopertha dominica (F.) (Coleoptera : Bostrychida).

Abstract

The effect of high and low temperature and microwave radiation on the adult of the lesser grain borer, Rhyzopertha dominica (F.) infested wheat seeds was studied. At high temperature (55°C), 29% of the death occurred after 30 minutes and the complete death occurred after 60 minutes. The lethal time of 50% mortality (LT50) and lethal time of 90% mortality (LT90) values were 36.96 and 63.4 minutes. Cold temperature (-7°C) caused 12% mortality after 20 minutes and complete succumb was obtained after 75 minutes. The LT50 and LT90 values were 38.6 and 71.3 minutes. Microwave at power of 2450 MHZ caused 33% mortality after 10 seconds and 100% mortality after 35 seconds. The LT50 and LT90 values on this power were 12.8 and 26.3 seconds. The mean germination rate of wheat seeds was 5% for microwave treatment (2450 MHZ, 30 seconds). However, 70% germination rate was achieved when the seeds were exposed to low temperature (-7°C, 3 months), and 77.5% when high temperature (55°C, 60 minutes) were used. In conclusion, the present study showed that, cold temperature (-7°c), high temperature (55°c), and microwave radiation had been successfully controlled R. dominica in a short period of time, however, microwave radiation had adverse effects on the germination of wheat seeds. Radiation seeds should therefore not be used in planting.