Resistance Monitoring Of Spodoptera Litura And Development Of Peticide Formulations

With the extensive use of chemical pesticides. Spodoptera litura has became resistant to variety of pesticides.However, the degree of resistance is not very clear, so there are lots of blindness in chemical control of Spodoptera litura in the field. Thus. it is necessary to monitor Spodoptera litura resistance and to understand the status of the field resistance development. in order to develop pests approach strategy better. Moreover. the situation of field pests" occurrence is complex and a variety of pests usually occur at the same time. So single medicament cannot achieve a broad insecticidal spectrum. Pharmaceutical compounding is an important way to expand the scope of prevention and to reduce the cost of prevention. But with people valuing environmental protection. traditional formulations withdraw from the market gradually due to a variety of environmental problems. So it is needed to develop environmentally friendly formulations, and environmentally friendly suspensions will be the best choice.1The resistance monitoring and the resistance stability analysis of Spodoptera lituraAs measured by the leaf immersion method, Spodoptera litura has the strongest sensitivity to emamectin-benzoate, chlorantraniliprole. hexaflumuron. chlorfluazuron. indoxacarb. chlorfenapyr, with LC50less than4mg a.i./L. For spinetoram. metaflumizone. spinosad, profenofos, chlorpyrifos, fipronil, endosulfan, pyridalyl, beta-cyfluthrin, cyhalothrin. deltamethrin. diafenthiuron. tebufenozide. LC50is between10-100mg a.i./L While for bifenthrin, thiodicarb. avermectins, acetamiprid. the activity is poorer. with LC50greater than100mg a.i./L. Resistance monitoring results show that Spodoptera litura in Huizhou has a very high level resistance to metaflumizone, achieving234times. There is a high level resistance to emamectin-benzoate and deltamethrin, with resistance multiple being around96times. There is a moderate level resistance to tebufenozide. thiodicarb, endosulfan, chlorantraniliprole, beta-cyfluthrin and cyhalothrin, with resistance multiple being10.682-30.959times. It is in low-level resistance stage to fiproni、 indoxacarb and spinosad. And the resistance to chlorfluazuron, hexaflumuron, chlorpyrifos, bifenthrin, chlorfenapyr, acetamiprid, spinetoram and pyridalyl is still in the sensitivity to sensitivity decline stage. Through the determination of resistance decline, we can analyze field resistance development and guide drug use. The results show that the resistance stability is low and the resistance decline speed is fast for Spodoptera lilura to deltamethrin. emamectin-benzoate. endosulfan,and the resistance to endosulfan decreases to sensitive stage. And the resistance stability to chlorantraniliprole. metaflumizone is high, stabilizing in the medium resistance level.2. Selection and formulation of several insecticide mixtures against Spodoptera lituraCo-toxicity factor of8different mixture ratio among8insecticide which were fipronil,cyhalothrin,bifenthrin,indoxacarb,tebufenozide,emamectin-benzoate,acetamiprid,he xaflumuron showed that there were synergic effects against Spodoptera litura in16insecticide mixtures and antagonistic effects in13insecticide mixtures.The combinations of indoxacarb+tebufenozide (1:8) with co-toxicity factor222which were the highest compared to other insecticide mixtures, and the combinations of acetamiprid+tebufenozide(24:1) with co-toxicity factor200were worth to be popularized. And then we shouid prohibit people from mixing several insecticide which showed antagonistic effects in the study. After optimization, screening, the superior formulation of the combinations of Indoxacarb+Tebufenozide as deflocculant were D500,4%; NS-500LQ,1.5%; magnesium aluminum silicate,1.5%; xanthan gum,0.15%; defoamer. HS-29,0.8;sodium benzoate,0.2%. The mean diameter of the preparation was1.467μm, the Suspension rate was more than90percent, the Surface tension of it which was diluted2000times still came to38.47mN/m despite it was stored for14days. Those information in the research had shown that the preparation’s higher stability and suitability for use and sales in areas of atypical warmth.This research found that the Spodoptera lilura has a high resistance on a variety of agents, and we analyzed their resistance stability, for the development of pest control method and resistance control provides the scientific basis; Selected16has a synergistic effect of ratio of pesticides, and indoxacarb+tebufenozide combination for pesticide processing and quality index were measured.25%indoxacarb·tebufenozide SC can effectively reduce the pesticide consumption, thus reduce the pesticide residue and control the cost, ideal for high temperature area promotion and the use of the moth, resistance to pest control, and governance has a positive meaning.