亚洲小车蝗痘病毒与化学杀虫剂混用的杀虫效果及对寄主主要解毒酶活性的影响

亚洲小车蝗痘病毒（Oedaleus asiaticus entomopoxvirus, OaEPV）作为一种增效剂，分别与马拉硫磷、毒死蜱、高效氯氰菊酯、氟氯氰菊酯 、溴氰菊酯化学杀虫剂混合饲喂亚洲小车蝗若虫，统计致死中浓度 LC₅₀ 和其混合使用后的增效比；测定虫体内与抗性有关的两种重要酶——羧酸酯酶（CarE）和谷胱甘肽 S-转移酶（GSTs）的比活力。结果表明：OaEPV 与化学杀虫剂混合饲喂亚洲小车蝗，OaEPV 与毒死蜱 、高效氯氰菊酯、氟氯氰菊酯、溴氰菊酯混用对亚洲小车蝗无明显的增效作用，OaEPV 与马拉硫磷混用，具有一定的增效作用，增效比为 1.42 倍。混剂感染亚洲小车蝗，除与溴氰菊酯混用外，虫体的中肠部位 CarE 的比活力都受到了明显的抑制作用，其中 OaEPV 与马拉硫磷混用下降了 4.21 倍，抑制作用最大。当 OaEPV 与氟氯氰菊酯、溴氰菊酯化学杀虫剂混用后，中肠部位 GSTs 受到了明显的抑制作用，而其脂肪体部位 CarE 和 GSTs 的变化无一定的规律性。结果提示痘病毒与农药混合处理时，病毒主要通过抑制中肠部位 CarE 比活力而增加了农药的杀虫效果。

Insecticidal effects of Oedaleus asiaticus entomopoxvirus in combination with chemical insecticides and effects on the main activities of detoxification enzymes of its host

Third-instar nymphs of Oedaleus asiaticus were fed on artificial diet mixed with combinations of O. asiaticus  entomopoxvirus (OaEPV) and the insecticides of malathion, chlorpyrifos, β-cypermethrin, cyfluthrin and deltamethrin, in which OaEPV was used as a synergist. Mortalities were observed, and LC₅₀ values and the synergic ratios were determined. The specific activities of two enzymes (carboxylesterase, CarE; glutathione S-transferases, GSTs) in relation to the pest resistance to insecticides were also assayed. The results showed that combinations of OaEPV and chlorp yrifos, β-cypermethrin, cyfluthrin, deltamethrin had no distinct synergism, whereas the combination of OaEPV and malathion was more effective than malathion alone in some degree. The synergic ratio of OaEPV to malathion was 1.42 times. Except del tamethrin, the specific activities of CarE in the midgut of O. asiaticus nymphs treated with mixtures of OaEPV and other insecticides mentioned above were inhibited obviously as compared to insecticide treatments alone. The highest inhibition ratio of CarE specific activity, 4.21 times, appeared when OaEPV was m ixed with malathion. The specific activities of GSTs in the midgut of O. asiaticus treated with the mixtures of OaEPV and cyfluthrin or OaEPV and delta methrin were evidently inhibited as compared to insecticide treatments alone. The specific activities of CarE and GSTs in the fat body of O. asiaticus treated with the mixtures, however, were not significantly changed as compared to insecticide treatments alone. The results suggest that OaEPV enhances the insecticidal effects of chemical insecticides against O. asiaticus by inhibiting the specific activity of CarE in the midgut.