Determination Of Sensitivity Of Aphis Gossypii To Insecticides In Shihezi And The Develop Of Pesticides Selected Kits

Xinjiang have a long cotton growing history, but The damage of Aphis gossypiiincreasingly in recent years. It becomes an important issue which affecting theproduction of cotton. For a long time, people relied on chemical pesticides to controlAphis gossypii, make it have a different levels of resistance to various pesticides, andthe extensive use of pesticides also killed many beneficial natural enemies, aggravatedthe difficulty of control. The root causes of rapid resistance development of Aphisgossypii is excessive spray volume. In order to improve chemical pesticides on theAphis gossypii have a targeted, scientific and high efficiency, this test measured theresistance development of Aphis gossypii, the synergistic effect of the pesticidemixture, established susceptible toxicity baselines of Aphis gossypii to4insecticides,and invented a fast and convenient pesticides selection kits. the conclusions arefollows:1. This experiments aimed to clear the sensitivity of Aphis gossypii in northernXinjiang to insecticides used commonly in production and market. The sensitivity ofAphis gossypii collected from147farm and Xinhu farm population were determinedto twelve insecticides of four types by filter paper diffusion method respectively. Theresults showed that the sensitivity of two Aphis gossypii populations was the same todifferent kinds of insecticides within the same type, and the differences to differenttypes of insecticides, and high sensitivity to imidacloprid, thiamethoxam, avermectin,and lower sensitivity to pyrethroid and organophosphorus compounds. According tothe results, insecticide types, dosages and application frequency should be controlledstrictly, in order to delay the resistance development of Aphis gossypii, and differentinsecticides should be applied rotationally and mixed reasonably.2. This test measured the synergism of acetamiprid and endosulfan against Aphisgossypii with dipping method, and confirmed the best ratio. The result showed thatthe mixed preparation of acetamiprid and endosulfan have notable synergistic effect atthe ratio of1:643, and then the CTC reached178.9. When the ratio of acetamiprid andendosulfan was1:1713according to effective components, the synergism of themixed preparation was obviously, the CTC reached to203.8. The tests showed thatthe combination of the two pesticides at the best ratio plays an important role inoptimizing insecticide’s toxic effect, prolonging insecticide’s service life and delayingthe resistance development of Aphis gossypii.3.This research used the method of residual film in glass tube with7h exposureto insecticides was employed for determining toxicity of insecticides to Aphis gossypiispecies, which were reared in room. we established susceptible toxicity baselines of Aphis gossypii to4insecticides. The result showed that the LC₅₀values of susceptibletoxicity baselines were0.85μg/cm²,0.042μg/cm²,0.0034μg/cm²,1.30μg/cm²forimidacloprid, acetamiprid, thiamethoxam and pymetrozine. The susceptible toxicitybaselines of Aphis gossypii to4insecticides established in this research could be usedas a reference for resistance monitoring.4. Based on the toxicity determination of acetamiprid and thiamethoxam onAphis gossypii, invented two pesticides selection kits by glass tube pesticidemembrane method, determined0.3448μg/cm²and1.0345μg/cm²as the distinctionconcentration of acetamiprid and thiamethoxam pesticides selection kits, and theoptimum storage temperature and storage period are4℃and150days, the bestdetection time was3h. The field test results of Pesticides selection kits was the sameto the results of Aphis gossypii resistance measure results. The kits allows people tofind out whether the resistance to insecticides on Aphis gossypii in prepared sprayingfield quickly, and make a rough estimate about the levels of resistance. It’s importantfor set a rational control measures on the Aphis gossypii, and improve chemicalpesticides have a targeted and high efficiency, determined a scientific concentration ofspraying, delay the resistance development of Aphis gossypii finally.