Toxicity Of Essential Oil And Diatomaceous Earth Applied Alone Or In Combination Against Adults Of Sitophilus Zeamais (L.) And Tribolium Castaneum (Herbst)

Essential oils are potential sources of alternative compounds to current used fumigants. They have low toxicity to warm-blooded animals, high volatility, and toxicity to stored-grain insect pests. One other promising alternative to conventional neurotoxins is the use of diatomaceous earth (DE), which is comprised of fossils of phytoplankton (diatoms) and acts through absorption of lipids from the insect cuticle and partially through abrasion. DEs have low mammalian toxicity and can be applied directly to the grain by using the same technology as that used for residual insecticides and can be removed from the grain during the milling process. However even when used at the label rates, DE has adverse effects on physical properties of grains, particularly bulk density and flow rate. This paper systematically studied the fumigation activity, contact toxicity, repellence activity and population inhibition effect of Cymbomopog Winterianus oil against the adults of Sitophilus zeamais and Tribolium castaneum, which aimed to provide technical support for applying Essential oil alone and in combination with DE to control stored-product pests, and also provide scientific foundation for simulating synthesizing the new insecticide of high efficiency, low poison, no residue, and no environmental pollution.(1) The control action of Cymbomopog Winterianus oil against the adults of S. zeamais and T. castaneum increasing obviously with time increasing. The contact toxicity, repellence activity and population inhibition activity of Cymbomopog Winterianus oil against the adults of S. zeamais and T. castaneum were researched at 28℃.The results of repellence activities indicated that the repellence activity of Cymbomopog Winterianus oil against the two stored insects were good, and increases with the concentration increasing, and decreases with time increasing. The population inhibition activity of Cymbomopog Winterianus oil against the two stored insects was also very good.(2) The DE has obvious effect on the two stored-insects. The toxicity of DE against the two stored insects were good, and increases with the concentration and temperature increasing.(3) The effect of essential oils and in combination with DE on two major stored-grain insect species was very good. The results indicated that the population inhibition activities of the three essential oils and DE against adults of S. zeamais and T. castaneum increases with concentrations. The study will provide scientific foundation for new insecticide of high efficiency, low poison, no residue, and no environmental pollution.