野外致倦库蚊对球形芽孢杆菌C_(3-41)的抗性

High-Level Resistance to Bacillus sphaericus C 3-41 in Field-Collected Culex quinquefasciatus

目的：探讨野外致倦库蚊对球形芽孢杆菌Ｃ３－４１的抗性。方法：为ＷＨＯ常规生物测定方法。结果：经连续８年的生物防制，野外致倦库蚊幼虫对球形芽孢杆菌Ｃ３－４１的抗性水平高达２４５４５倍，但对球形芽孢杆菌ＬＰ１－Ｇ未表现出抗性，而对苏云金杆菌以色列亚种（Ｂ．ｔｈｕｒｉｎｇｉｅｎｓｉｓｉｓｒａｅｌｅｎｓｉｓ）的敏感性却提高１倍。

Bacillus sphaericus C 3-41 larvicidal formulation has been continuously used to control Culex quinquefasciatus larvae for eight years in Dongguan, Guangdong .It has proved that this kind of formulation has high efficacy against the target larvae in early treatment period. Under the high continuous selective pressure, C.quinquefasciatus developed very high resistance to C 3-41 and the resistance level was calculated to be 24 545 -fold in comparison with the sensible larvae collected from the untreated areas. It also showed that the B.sphaericus LP1-G had the same toxicity against both susceptible and resistant larvae and B.thuringiensis subsp. israelensis was more active to the former than the latter.So we suggested B.thuringiensis israelensis could be used as a promising alternative for controlling the resistant larvae.