Safety Evaluation Of Three Aquatic Organisms By Neonicotinoid Insecticides

The origin of neonicotinoid insecticides are natural plant.These pesticides have a unique mechanism,good root systemic activity,low toxicity to mammal.As a kind of broad-spectrum efficient environmentally friendly pesticides,neonicotinoid insecticides are the most effective pesticides for insect pests with sucking mouthparts.Neonicotinoid insecticides were widely used and easy to enter the water environment.Researchers have detected this substance in multinational water bodies.Neonicotinoid insecticides have toxicity to non-target aquatic species.These pesticides affect the stability of aquatic ecosystem.This paper focused on the impacts of neonicotinoid insecticides on Chlorella vulgaris?Daphnia magna?Brachydonio rerio.Chlorella vulgarisis the representative of producers in aquatic ecosystems.Daphnia magna and Brachydonio rerio are representatives of consumers in aquatic ecosystems.Acute toxicity of eight neonicotinoid insecticides on test organisms were studied.Chronic effects were studied through direct and dietary exposure of neonicotinoid insecticides fed with algae cells.The data supports the need for evaluation and monitor the environmental impact of neonicotinoid insecticides.The LC50(96 h)of nitenpyram,acetamiprid,dinotefuran,thiamethoxam,imidacloprid,pymetrozine,clothianidin,thiacloprid on Brachydonio rerio are 589 mg/L,182 mg/L,539 mg/L,128 mg/L,237 mg/L,184 mg/L,134 mg/L,35.1 mg/L,according to "Experimental Guideline for Environmental Safety Evaluation of Chemical Pesticides",they all belong to low poisonous chemicals on Brachydonio rerio.The EC50(48 h)of nitenpyram,acetamiprid,dinotefuran,thiamethoxam,imidacloprid,pymetrozine,clothianidin,thiacloprid on Daphnia magna are 15.3 mg/L,32.6 mg/L,2.17 mg/L,0.0342 mg/L,2.17 mg/L,7.09 mg/L,2.82 mg/L,26.6 mg/L,according to“Experimental Guideline for Environmental Safety Evaluation of Chemical Pesticides",acetamiprid,thiamethrin,acetamidine belong to low poisonous chemicals on Daphnia magna,imidacloprid,dinotechin,pymetrozine,belong to moderately toxic catalogue,thiamethoxam are virulent for Daphnia magrna.The EC50(72 h)of nitenpyram,acetamiprid,dinotefuran,thiamethoxam,imidacloprid.pymetrozine.clothianidin,thiacloprid on Chlorella vulgaris are 15.8 mg/L,9.46 mg/L,38.3 mg/L,3.33 mg/L,13.5 mg/L,18.9 mg/L,33.0 mg/L,57.8 mg/L,according to "Experimental Guideline for Environmental Safety Evaluation of Chemical Pesticides",they all belong to low poisonous chemicals on Chlorella vulgaris.Pymetrozine and clothianidin have significant negative interference on the survival and reproduction of Daphnia magna through the food chain.Nitenpyram,acetamiprid and dinotefuran have less interference on the survival and reproduction of Daphnia magna through the food chain.Thiamethoxam,imidacloprid and thiacloprid have less interference on the survival of Daphnia magna through the food chain,but they have significant negative interference on the reproduction of Daphnia magna through the food chain.Chlorella vulgaris cells are risky for the survival and reproduction of Daphnia magna after being contaminated with subinhibitory concentrations of some neonicotinoid insecticides.