Studies On The Controlling Activities Of Prickly Ash Extracts Against Sitophilus Zeamais Motschulsky And Tribolium Castaneum Herbst

During the period of storage, grain could be damaged by insect, mite, and microorganism pests, which could cause huge quality and quantity losses of stored grain. Nowadays, it seems that the weapons to protect stored grain against insect pest are decreasing, so new fumigants which are safe, environmentally friendly and efficient are urgently needed. Containing many insect-killing materials, Prickly ash is a potential insecticide from plants with good fragrance, and is also safe to human and animals, free from pollution to environment and so on. This paper systematically studied the fumigation activity, contact toxicity, repellence activity, attractant activity and population inhibition effect of several prickly ash extracts against the adults of Sitophilus zeamais, Tribolium castaneum and other stored-product pests, which aimed to provide technical support for applying prickly ash extracts 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 fumigation activities of prickly ash essential oils and spicy elements against several stored-product pests1.1 The fumigation activities of prickly ash essential oils and spicy elements against the adults of 5. zeamais and T. castaneumThe LC₅₀ s of green prickly ash essential oil, red prickly ash essential oil, primary spicy element and second spicy element against the adults of S. zeamais and T. castaneum were investigated by fumigation in sealed jar after 48 h and 72 h at 30℃. The results indicated that the highest of LC₅₀s was primary spicy element, followed by second spicy element, red prickly ash essential oil and green prickly ash essential oil. The effects of treatment time and temperature on fumigation activities of green prickly ash essential oil and red prickly ash essential oil were further researched. The results indicated that the longer the fumigation time was, the lower LC₅₀S of two essential oils to S. zeamais and T. castaneum would be, which showed that the lasting duration of the two essential oils was relatively long. From 20℃to 35 V, the higher the temperature was, the higher the corrected mortality of two essential oils to S. zeamais would be, and the corrected mortality of two essential oils to T. castaneum was at first increasing and then decreasing with the temperature rising.1.2 The fumigation activities of prickly ash spicy elements against four stored-product insect pests in simulative storehousesThe fumigation activities of primary spicy element and second spicy element against the adults of S.zeamais, T.castaneum, C.pusillus and L.bostrychophila were studied in simulative storehouses of wheat. The results showed that fumigation activity of second spicy element was better than that of the primary spicy element. By comparing the different wheat layers, the mortality at the upper layer was the highest, the mortality at the lowe(?) layer was the lowest. As for different kinds of pests, two kinds of spicy elements had the best fumigation effects against L. bostrychophila and C. Pusillus, the next was against S. zeamais, and the worst was against T. castaneum.2 The contact toxicities, repellence activities and attractant activities of prickly ash extracts against adults of S. zeamais and T. castaneumThe contact toxicity, repellence activity and attractant activity of green prickly ash essential oil, red prickly ash essential oil, primary spicy element, second spicy element, prickly ash powder, branch powder and powder after extractioning against the adults of S. zeamais and T. castaneum were researched at 30℃. The results of contact toxicities experiment indicated that contact toxicities of several prickly ash extracts against the adults of S. zeamais and T. castaneum were different. The contact toxicities of prickly ash essential oils and spicy elements were better than that of three powdery prickly ash extracts. The contact toxicity of primary spicy element against S. zeamais adult was the best, the poorest was that of red prickly ash essential oil. The contact toxicity of second spicy element and green prickly ash essential oil against T. castaneum adult was reletively good, the poorest was that of red prickly ash essential oil in four prickly ash extracts. The contact toxicity of three kinds of powdery prickly ash against the two kinds of stored-product pests were not obvious.The results of repellence activities and attractant activities indicated that the repellence activity of green prickly ash essential oil against 5. zeamais adult was better than that of red prickly ash essential oil. The repellence activities of primary and second spicy elements against adults of T. castaneum were good, and increases with the concentration increasing, and decreases with time increasing. The attractant activities of the two prickly ash spicy elements against adults of S.zeamais were very good.3 Controlling activities of prickly ash extracts against the adults of S. zeamais and T. castaneum by mixing with grain3.1 The lethal effect of three kinds of prickly ash powder against adults of 5. zeamais by mixing with wheatThe controlling activities of prickly ash powder, branch powder and powder after extractioning against adults of 5. zeamais were studied by mixing with wheat in different treatment time at 30°C. The results indicated that the control action of three kinds of prickly ash powder against adults of S. zeamais increase obviously with time increasing, and the maximum value of corrected mortality can reach 99% after 21 days. Therefore, the efficacy of prickly ash powder could be fully improved as treatment time increased, but there is no significant difference among these three kinds of prickly ash powder.3.2 The population inhibition activities of prickly ash extracts against the adults of T. castaneumThe population inhibition activities of green prickly ash essential oil, red prickly ash essential oil, primary spicy element, second spicy element, and acetone soak solution, alcohol soak solution, boiling water solution of prickly ash powder, branch powder and powder after extractioning against the adults of T. castaneum were researched at 30℃. The results indicated that the population inhibition activities of prickly ash essential oils and spicy elements against adults of T. castaneum increases with the concentrations. The population inhibition activity of primary spicy element was the best, and that of two prickly ash essential oils were the poorest. The population inhibition activities of three kinds of powdery prickly ash soak solution and boiling water solution against adults of T. castaneum was not obvious, and the inhibition ration were less than 50%.