Resistance of diamondback moth( Plutella xylostella L.) population against eight kinds of insecticides in Luliang County of Yunnan Province in China was determined in laboratory by leaf dipping method in autumn of 2009 and spring of 2010. The monitoring results showed that diamondback moth population in Luliang County of Yunnan Province had produced extremely high resistance against beta-cypermethrin and avermectin; LC50in autumn of 2009 were 1 035. 21 and1 055. 19 mg / L,while those in spring of 2010 were 9. 55 and 13. 84 mg / L,respectively; the resistance ratios were from 291. 61 to 692. 00. The diamondback moth population had moderately high resistance to spinosad,indoxacarb and chlorfluazuron; LC50in autumn of 2009 were 1. 59,2. 80 and 23. 97 mg / L,while those in spring of 2010 were 13. 83,24. 57 and 42. 73 mg / L,respectively; the resistance ratios were from13. 25 to 129. 98. The diamondback moth population was sensitive to diafenthiuron,BT and chlorfenapyr; LC50in autumn of 2009 were 16. 51,47. 40 and 0. 85 mg / L,while those in spring of 2010 were 1. 34,3. 38 and 1. 60mg / L,respectively; the resistance ratios were from 0. 77 to 8. 45. The resistance of diamondback moth population in Luliang County of Yunnan Province against eight kinds of insecticides successively were diafenthiuron < BT preparations < chlorfenapyr < spinosad < indoxacarb < chlorfluazuron < beta-cypermethrin
Resistance of diamondback moth ( Plutella xylostella L. ) population against eight kinds of insecticides in Luliang County of Yunnan Province in China was determined in laboratory by leaf dipping method in autumn of 2009 and spring of 2010. The monitoring results showed that diamondback moth population in Lu- liang County of Yunnan Province had produced extremely high resistance against beta-cypermethrin and avermectin; LC50 in autumn of 2009 were 1 035.21 and 1 055.19 mg/L, while those in spring of 2010 were 9.55 and 13.84 mg/L, respectively; the resistance ratios were from 291.61 to 692.00. The diamondback moth population had moderately high resistance to spinosad, indoxacarb and chlorfluazuron; LC50, in autumn of 2009 were 1.59, 2.80 and 23.97 mg/L, while those in spring of 2010 were 13.83,24.57 and 42.73 mg/L, respectively; the resistance ratios were froml3.25 to 129.98. The diamondback moth population was sensitive to diafenthiuron, BT and chlorfenapyr; LC50 in autumn of 2009 were 16.51, 47.40 and 0.85 mg/L, while those in spring of 2010 were 1.34, 3.38 and 1.60 mg/L, respectively; the resistance ratios were from 0. 77 to 8.45. The resistance of diamondback moth population in Luliang County of Yunnan Province against eight kinds of insecticides successively were diafenthiuron 〈 BT preparations 〈 chlorfenapyr 〈 spinosad 〈 indoxacarb 〈 chlorfluazuron 〈 beta-cypermethrin 〈 ave rmectin, and the resistance in spring was higher than that in autumn.