The Monitoring And Resistance Management Of The Diamondback Moth, Plutella Xylostella L. In Zhangjiakou

This paper monitored the resistance level of diamondback moth(Plutella xylostella) to insecticides commonly used in Zhangjiakou respectively in 2007,2009 and 2010, screened the mixed distribution reagent in the laboratory, carried out the field efficacy trials, and proposed the system of controlling resistance of DBM. The results indicated that:(1) The DBM of zhangjiakou areas had no resistance to methomgl, Bt, chlorfenapyr, spinosad, tebufenozide, dichlorbenzuron, cypermethrin, beta-cypermethrin, chlorpyrifos, phoxim in 2007, because of the resistance index within 4-fold.The field population of DBM had developed 12.3-fold resistance to avermectins, which has been reached moderate resistance level. It had developed 9.4-fold resistance to fipronil, which has been approached moderate resistance level. It had developed 6.9-fold resistance to emamectin-benzoate, which has low resistance level.The DBM of zhangjiakou areas had no resistance to tebufenozide, fipronil, spinosad, diafenthiuron, cartap in 2009, owing to the resistance index within 4-fold.It were very susceptible to Bt and indoxacarb, because of the resistance index respectively 0.84 and 0.02.It had developed 10.45-fold and 11.10-fold resistance to avermectins and beta-cypermethrin, which has been reached moderate resistance level.The resistance level of the DBM of Zhangjiakou area to tebufenozide, fipronil, spinosad, diafenthiuron, cartap in 2010 wsa same as in 2009. It was susceptible to beta-cypermethrin and indoxacarb, due to the resistance index less than 1. It had developed 7.5-fold resistance to Bt, has produced resistance. It has developed 37.67-fold resistance to avermectins, which has been approached high resistance level.(2) It was screened the mixed distribution reagent mainly containing avermectin, which used the avermectin-susceptible strain. The results indicated that 5% kungfu. avermectin EC of different proportion for controlling the DBM had better synergistic action. The synergistic action of AB3 was most strongest when compared with others.(3) The results of field trials showed that effects of 2.5% spinosad SC,8000IuBtWP,10% chlorfenapyr SC,20% diafenthiuron EC and combined flotation reagent 5% kungfu. avermectin EC were significantly better than that of 5% fipronil SC and 1.8% avermectin EC, which efficacy against the DBM were 39.4%-43.2%,79.5%-81.6% and 90.8%-95.3%, respectively after 1d treatment,4d treatment and 7d treatmet. Which can be recommended to use in field. Biology preparation 8000IuBt has little damage and selectivity to Cotesia plutellae ovary, which is beneficial to the balance of nature.(4) There are mainly 10 species of predatory enemies of the DBM in zhangjiakou area, which include lycosa pseudoannulats, clubiona japonicola, erigondium gramincola, misumenops tricuspidatus in arachnoida and propylaea japonica, heterochromatic ladybug, seven spot ladybird, chinese green lacewing, chrysopa septemfunctata wesmore, cicindela chinensis degeer in insecta.The number of the spiders accounted for 86.63% of the total.The population of Lycosa pseudoannulats and erigondium gramincola were dominant. (5) The system of resistance management of DBM was generalized in vegetable base of Kangbao County, Guyuan Gounty, Ghangyi Gounty and Ghangbei Gounty in Zhangjiakou in 2007-2009. It was promoted 3533.33hm2, total output value of 17.028 million yuan added.