Toxicity And Toxicological Effects Of Two Neonicotinoids On Japanese Quail (Coturnix Japonica)

Birds play an important role in the ecosystem, and it is also a symbol of the ecologicalbalance. Not only do the birds have an important contribution in the eradication of pests,vermin, and the maintenance of ecological balance, it is aslo an important food of human. Inrecent years, large-scale use of chemical pesticides not only directly harm the environmentand the survival of the state of bird life, but also cause subsequent toxic effects in itsaccumulation in the body through the food chain. Neonicotinoid insecticides whichrepresented by imidacloprid and thiamethoxam have become one of the preferred pesticidesagainst Homoptera, Coleoptera, Diptera and Lepidoptera pests instead of traditional pesticides,because of its efficient, broad-spectrum and good root absorption, and its stomach poisoningand contact action. It can use spray and seed broadcasting.In this paper, the way of one-time oral gavage and oral feeding are used to compare theacute toxicity on the Japanese quail of the two neonicotinoid compounds; The results showthat the LD50of imidacloprid and thiamethoxam on Japanese quail were30.25mg·kg-1·bw-1,163.14mg·kg-1·bw-1respectively. The acute oral toxicity of imidacloprid on Japanese quail ishighly toxic and thiamethoxam is moderate toxicity, according to the acute toxicity criteria forthe classification of birds. The LC50of imidacloprid on Japanese quail was1455.11mg·kg-1·feed-1, and the thiamethoxam was higher than2000mg·kg-1·feed-1, the acute feedingtoxicity of both these two compounds on Japanese quail are low toxicity according to theacute toxicity criteria for the classification of birds.Dose escalation accumulation coefficient methods are used to evaluate the strength of thecumulative toxicity of the two pesticides. After the accumulation trial, the accumulationcoefficient of imidacloprid is5.24, and thiamethoxam is higher than five, the cumulativetoxicity of imidacloprid and thiamethoxam on Japanese quail were slight accumulationaccording to the cumulative toxicity evaluation criteria, and it also provide a reference of doseselection for the sub-chronic toxicity test. On the basis of acute toxicity and cumulativetoxicity test, the sub-chronic toxicity of the two pesticides was studied through feed exposure,and the toxic effect of target organs and the maximum effective dose of the imidacloprid andthiamethoxam are preliminary determined by observing the symptoms of poisoning, the bodyweight and food consumption, blood biochemical enzymes indicators. The main results are asfollows: The body weight and food consumption of Japanese quail treated by the high-dose oftwo neonicotinoid insecticides were significantly decreased on the subchronic text comparedwith the control. The liver organ coefficient was significantly higher, and on the blood biochemical parameters, the ALT, ALP and CREA were significantly higher than that in thecontrol. The results showed that the target organ of imidacloprid and thiamethoxam on theJapanese quail is the liver, the maximum no-effect dose29.10mg·kg-1·feed-1,150mg·kg-1·feed-1respectively.In summary, birds will produce a series of toxic physiological response after long-termexposure to the neonicotinoid pesticides or ingest seeds treated by drug. The results indicatethat the acute toxicity of thiamethoxam to Japanese quail was significantly lower thanimidacloprid, and it also has an effect of aversion and antifeedant. Therefore, when the twokinds of pesticides have the same control effect, it will be the first choice to selectthiamethoxam on spraying or seed dressing to reduce the hazards of pesticides on birds.