铃虫对氰戊菊酯抗性和敏感品系的选育

LABORATORY SELECTION FOR FENVALERATE RESISTANT AND SUSCEPTIBLE STRAINS IN COTTON BOLLWORM,HELIOTHIS ARMIGERA (HUBNER)

用氰戊菊酯对来自阳谷的棉铃虫（ＹＧ）Ｈｅｌｉｏｔｈｉｓａｒｍｉｇｅｒａ（Ｈｕｂｎｅｒ）进行抗性品系的筛选。在１５代期间经过９代的室内选育，获得抗性品系（Ｆｅｎ－Ｒ），抗性倍数高达２４６３倍，筛选后Ｆ１，代ＬＤ５０值（２４．１４１２ｇ／头）比筛选前Ｆ１代ＬＤ５０值（０．２０２０ ｇ／头）提高了１１９．５倍。对来自偃师的棉铃虫（ＹＳ）进行了连续两代单对筛选，得到敏感品系（Ｆｅｎ－Ｓ），敏感品系的ＬＤ５０值为０．０１１６ｇ／头，接近１９８３年东台敏感品系的ＬＤ５０值（０．００９８ｇ／头）。Ｆｅｎ－Ｒ抗性品系筛选前后分别测定了七种杀虫剂的剂量－死亡回归线，发现Ｆｅｎ－Ｒ抗性品系对溴氰菊酯［ＬＤ５０（Ｆｅｎ－Ｒ）ＬＤ５０（ＹＧ）＝５．２Ｘ］和氯氰菊酯（２．５Ｘ）具有一定程度的交互抗性；而对功夫菊酯（０．６６Ｘ），氯菊酯（０．８７Ｘ）、灭多威（０．７４Ｘ）及久效磷（１．５Ｘ）没有交互抗性。氰戊菊酯加Ｐｂ的增效试验结果表明棉铃虫对氰戊菊酯的抗性主要是由于多功能氧化酶的代谢作用。毒理学资料还暗示抗性为多因子（基因）的。

fenvalerate resistant strain (Fen-R) of cotton bollworm, Heliothis armigera(Hubner), was obtained by laboratory selection of a strain (YG) collected fromYanggu County, Shandong Province in 1990 after nine selections with fenvalerateduring fifteen generations, and exhibited about 2463-fold resistance to this insecticideas compared with a susceptible strain collected from Dongtai County, JiangsuProvince in 1983. The LD50 value (24. 1412g/larva) in F15 generation after selection increased to 1 19.5-fold as compared with the LD50 value (0.2020 g/larva) of F1.A fenvalerate susceptible strain (Fen-S) was developed by selection of progenies thatresulted from single-pair matings of cotton bollworm collected from Yanshi County,Henan Province, under conditions free of insecticides, and its LD50 was 0.0116 g/larva, close to that of Dongtai susceptible strain in 1983.Dose-mortality regressions were estimated for seven insecticides applied to YGstrain before selection treatments and to Fen-R strain, respectively. A spectrum ofcross-resistance was detected to deltamethrin [LD50(Fen-R)/LD50(YG) = 5.2X] andcypermethrin (2.5 X ), but no cross-resistance to cyhalothrin (0.66 X ), permethrin(0.87 X ), methomyl (0.74 X ), and monocrotophos (1.5 X ). The studies on synergismof fenvalerate+Pb in Fen-R strain showed that resistance was due principally to themetabolic (multiple function oxidase) mechanism. Toxicological data suggested thatmore than one factors (genes) were responsible for resistance to fenvalerate in Heliothis armigera (Hubner).