| Chlorantraniliprole is the first broad-spectrum insecticide with a new neighbor amide groups benzamides chemical structure, which was discovered and produced by the DuPont Company in2007. The biggest advantage of this pesticide is its unique chemical structure, novel mode of action, and efficient broad-spectrum control effects and highly environmental and ecological security. For a long time, most people focus on the evaluation of pesticides to control effect of natural enemies and its side effects or benefice. But in recent years, Hormesis effects of pesticides on natural enemies of pests attracted wide attention at home and abroad. The core of Hormesis effect theory is the impact of toxic compounds on biological performance of low-dose stimulation, high-dose inhibition phenomenon. This paper intends to employ wolf spider Pardosa pseudoannulata as test organisms and Chlorantraniliprole as test agents, to investigate the effects of low-doses pesticides on natural enemies in growth, development, predatory function and activity ofenzymes in vivo and etc. In order to coordinating chemical control with biological control and provide new ideas.In this article, we describe a model-based approach to detect and estimate hormesis when enhanced responses are observed in dose-response experiments. We propose using "ratio of the area under the hormetic zone (AUCh) and the area under the nonlinear dose-response curve from zero to ZEP (AUCZEP)" as a measure of hormesis. The results showed that the benchmark dose (BMD) values was1.6451mg/L, and the benchmark dose lower (BMDL) than95%confidence interval limits was1.56287mg/L. Employing weight indicator of P. pseudoannulata, the Hormesis effect model was f(x)=0.0029+0.0116x-0.0309x2, Zero Equivalent Point(ZEP) was0.3754mg/L. Chlorantraniliprole for the weight of Pardosa pseudoannulata hormesis effect of low-dose intensity was20.01%.On this basis, a low-dose Chlorantraniliprole (concentration:0.3mg/L,0.6mg/L and 1.2mg/L) treatments were intended to Pardosa pseudoannulata, which were investigated for its growth, development, predatory function and activity of enzymes in vivo. The main research results are as follows:After the low-dose Chlorantraniliprole treatments, the effect on the F0females of the spider’s life-span and fecundity was not significant. But it can significantly extend each developmental stages of the F1generation and improve the F1females of the spider’s life-span and fecundity, showing its strong stimulating effect. While effects of low-dose Chlorantraniliprole on predation function is very significant, reducing the amount of predation, grazing rates and search efficiencies. Holling model parameters showed that pesticide treatments intended to attack the instantaneous rate (a’) has reduced to varying degrees, and decreases with increasing dose. The processing time of prey (Th) have increased the maximum amount of prey are also reduced compared to the control group. Each treatment group a’/Th values were reduced compared with the control group, and decreased with increasing dose, indicating that with increasing doses of pesticides, its ability to control insects gradually weakened. Low-dose Chlorantraniliprole can significantly improve the body Pardosa intended carboxylesterase detoxification enzymes and function oxidase activity, reducing the target enzyme acetylcholinesterase activity. The study will contribute to the rational use of pesticides in rice fields, to provide theoretical guidance for the protection of natural enemies while avoiding disadvantages, to maximize the role of natural enemies to control pests. |
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