부산대학교 도서관

Azadirachtin contained in Neem extract has the properties of inhibiting the feeding and growth of 413 kinds of insects such as Lepidoptera, Hemiptera, Locustaceae, and Nematodes. This study evaluated the acute toxicity of bioexposure to Daphnia magna, which has excellent toxic effect recognition effect, in order to analyze the effect of Neem extract biological pesticides on the aquatic ecosystem. Neem extract biopesticides used for acute toxicity evaluation contain about 1.6% of Azadirachtin, an insecticidal active ingredient. The first dilution ratio is at least 2.00x10-3, azeotrope 2 is 5 concentrations, the second dilution ratio is 1.00x10-4, azeotrope 3 is 5 concentrations, the dilution ratio in this experiment is 1.00x10-4, azeotrope 2 is the lowest. Acute toxicity test against daphnia was performed a total of 3 times with 5 concentrations. Neem extract biological pesticide 48hr-EC50 calculated by logistic method was 518.53 μg/L of Azadirachtin concentration, NOEC was 19.75 ㎍/L of Azadirachtin, and predicted no-effect concentration (PNEC) was 0.52 ㎍/L of Azadirachtin. It was L. The biological pesticides used in this study are sprayed at a rather high concentration in the area of use. However, due to dilution by rainfall and adsorption and infiltration into the soil, a decrease in the amount discharged into the watershed is expected. Azadirachtin has biodegradation and photodegradation characteristics by microorganisms, so it is thought that the effect on the ecosystem in the sprayed area and water body will be different.