Study On Population Dynamic And Control Technology Of Mythimna Separata(walker) In Shanghai Farm

Wheat is one of the main food crops in China,while armyworm is one of the important obstacles to the safe production of wheat.For a long time,the control and prevention of armyworm has mainly depended on chemical pesticides.Its long-term use has increased the risk of exceeding pesticide residue,increasing pest resistance and the resurgence of pests.It is an urgent problem to solve the sustainable control of wheat pests.Shanghai Farm is located in Dafeng District,Yancheng City,Jiangsu Province,also refers to the coastal area of Jiangsu Province.Based on study of dynamics of local armyworm,this paper explains occurrence regularity of armyworm in coastal areas of Jiangsu Province;Straw oviducts and sex attracts are applied to explore the non-chemical control techniques of wheat armyworm.At the same time,several kinds of pesticides with high efficiency,low toxicity and low residue are screened out.The results provide a new technique for the green control of wheat armyworm in Shanghai farm.1.Farm armyworm wheat field population dynamics of shanghai survey found that the temperature stability in 18? to 22? armyworm adults in local,three moth peak appears in'the field,on April 10Th,the moth peak is highest,trap to 230 head armyworm adults the effect of sugar and vinegar in the field was better than that of sex lure.Among the three varieties of yangmai 23,yangfu maimai 4 and zhemasi 12,moths were attracted relatively high and the insect quantity of zhenmai 12 was low,indicating that zhenmai 12 had certain resistance to slime worms.2.The results showed that there was a good correlation between the number of eggs and the population dynamics of field systematic investigation.4 sexual attractant traps were placed/mu,with the maximum amount of traps reaching 10.58 heads/basin.At 15d,the control effect reached 75.00%;At 25d,the control effect reaches 67.06%,which is the best.The use of grass to lure eggs can also significantly reduce the amount of insects in the 'field.4 mu were placed,and the maximum amount of egg induction was 47.33 head/branch per grass.The larvae control effect at 15d was 81.34%,respectively.At 25d,72.48%grass was placed in 8 mu,which had the best control effect on slime worm.3.The control effects of different insecticides on wheat armyworm shows that those six insecticides are effective to its control,including 10%high efficiency cypermethrin,25 g/L deltamethrin,100g/L bifenthrin,5%chlorobenzamide,bacillus thuringiensis and 25%cyanothion.All of them are above 97%,and there is no significant difference-between them.However,the cost of 10%high efficiency cypermethrin is the lowest in terms of field production cost control,which is 0.9 yuan/mu,and the cost of other chemicals is more than 1.5 yuan.