Evaluation of Acute Toxicity of Daphnia of Natural Pesticides Based on Derris Extract

다국어 초록 (Multilingual Abstract)

Recently, as the development and distribution of eco-friendly biological pesticides made using natural raw materials without using chemical materials such as organic synthetic pesticides and chemical fertilizers are increasing, it is necessary to evaluate the impact of these natural pesticides on the aquatic ecosystem. Product “B”, which has natural plant extract as its main ingredient, consists of Derris extract, garlic oil, paraffin oil, and supplements. The main ingredients are Rotenone, Diallyl disulfide, Paraffin oil, etc. Rotenone, which acts as an insecticide, contains 2.5%. Rotenone is widely used as a natural herbicide and insecticide, and is known to be particularly toxic to fish.
In this study, an acute toxicity test for daphnia using Daphnia magna was performed to evaluate the toxicity that residues of this natural pesticide may have on the aquatic ecosystem. According to the seller’s recommended usage method, it is suggested to dilute the product stock solution 1,000 times for use, so an experiment was conducted to observe the swimming inhibition rate by applying a dilution azeotrope 2 starting from 1,000 times (Rotenone concentration 25,000 ㎍/l), and Sigma-plot was used. As a result, the half effect concentration (48hr EC50) was 18.7 million times dilution (Rotenone concentration 1.33 ㎍/l), and the observed no effect concentration (NOEC) was 80 million times dilution factor (Rotenone concentration 0.31 ㎍/l).
The observed minimum effect concentration (LOEC) was 40 million times (Rotenone concentration 0.63 μg/l). Rotenone is a substance that is rapidly decomposed in soil or water and has a half-life of 1 to 3 days, and its insecticidal power decreases with time.
It is known, and considering the natural decomposition effect, the amount of crops sprayed, and the dilution by rainfall, the effect on the aquatic ecosystem is thought to be different from the instantaneous toxicity when sprayed.