辛硫磷和溴氰菊酯混剂对家蝇抗性发展的影响

以家蝇(Musca domestica vicina Macquart)为试虫，用辛硫磷溴氰菊酯单剂及不同配比的混剂进行汰选试验。所有混剂选育的家蝇抗性发展都很缓慢，而单剂抗性发展都很快。增效试验表明，辛硫磷与溴氰菊酯混配有明显增效作用，特别是对抗性品系。生化分析结果表明，对澳氰菊酯的抗性发展与酯酶的酶活升高有关。对辛硫磷抗性发展与多功能氧化酶的酶活升高和乙酰胆碱酯酶敏感性降低有关。混剂选育的家蝇其对单剂的敏感性的变化及酶系的变化，随着混剂的配比而变化。

THE EFFECT OF MIXTURES OF PHOXIM AND DELTAMETHRIN ON DEVELOPMENT OF RESISTANCE Iff HOUSEFLY

The effect on development of resistance in the housefly Musca domestica vieina Macquart on deltamethrin alone and mixtures of deltamethrin and phoxim by continuous selection was studied in the laboratory. All mixtures markedly lowered the level of resistance than deltamethrin or phoxin applied alone and no notable changes in sensitivity were observed even after selection for 18 generations. The suppressive effect was due to reduction of selection pressure of each insecticide in the comb ination on respective generations and synergistic action between deltamethrin and phoxim in the mixture. The most effective combination of deltamethrin and phoxim was found to be l:l(w/w) for deltamethrin resistance strain and l:1000(w/w) for phoxim resistance strain. All strains of the housefly selected by the mixture displayed almost no resistance to the initial single insecticide, either deltamethrin or phoxim. The metabolic mechanism of selected strains of house fly was investigated through testing the activities of detoxification enzyme and ACHE.