Effect Of Microwave On Tribolium Castaneum Survival

Tribolium castaneum, one of the storage pests in wheat flour, is mainly killed by chemical fumigation with phosphine and methyl bromide, but the method of chemical fumigation have the problem of food safety and environmental pollution. With the propertyies of thermal effects and non-thermal effect, microwave can effectively inhibit grain pests, but the stronger intensity of which will impair the quality of grains. At present, the lethal mechanism of low-energy density microwave on storage pests was not clear. In this study, the effects of microwave and heat conduction on Tribolium castaneum survival were investigated.The purpose of this study was to explore the lethal mechanism of Tribolium castaneum treated with low-energy density microwave and to provide a theoretical basis of pest control with microwave. The main conclusion of the study were as follows:1. Effect of microwave on the temperature of wheat flour. The temperature of wheat flour treated by low-energy density microwave and the heating time showed a good linear relationship. But after the water bath, the temperature of wheat flour was non-linear relationship with time, and an upward trend in temperature gradually become smaller.2. Effect of microwave on Tribolium castaneum lethality rates. After low-energy microwave and water bath treatment, precision analog equation of lethality rates was obtained. The semi-lethal temperature (48℃) and the lethal temperature (50℃) of Tribolium castaneum treated by microwave were lower than the semi-lethal temperature (50℃) and the lethal temperature (52℃) trwated by water bath.3. After low-energy microwave treatment, Tribolium castaneum's water content, pH, crude protein content, crawling speed, the second generation of hybrid hatching rate, alkaline phosphatase and acetylcholinesterase activity decreased, peroxide value increased, the total free amino acids content increased, the molecular weight of protein subunits become smaller,, amino acid composition changed in content, DNA damaged, almost no changes in epidermal morphology, cell structure damaged to a certain extent.4. The lethal mechanism of low-energy density microwave on Tribolium castaneum. After treated with low-energy microwave, Tribolium castaneum's cell structure was damaged, cell membrane permeability increased, proline synthesis was inhibited, the genetic material such as DNA was damaged to some extent, and characteristics of reproductive and behavior were affected to a certain extent, the activity of heat resistance enzyme reduced and the central nervous system was damaged.