二点叶螨对氧乐果、甲氰菊酯、四螨嗪及螨嗪菊酯混剂的抗药性

以兰州吐鲁沟公园金花忍冬植物上采集的二点叶螨为敏感种群,在室内盆栽菜豆苗上饲养繁殖后分别用氧乐果、甲氰菊酯、四螨嗪及螨嗪菊酯(甲氰菊酯 四螨嗪)混剂喷雾处理20代,获得二点叶螨抗氧乐果种群(抗性指数RF=35.84倍)、抗甲氰菊酯种群(RF=479.79倍)、抗四螨嗪种群(RF=67.26倍)以及抗混剂螨嗪菊酯种群(RF=26.75倍)。用生化法测定离体酶活性的结果表明,上述四个抗性种群的形成与体内羧酸酯酶、磷酸酯酶、谷胱甘肽转移酶的活力增加及乙酰胆碱酯酶的活性降低有关。4个抗性种群对常用15种供试药剂交互抗性测定结果表明,氧乐果、甲氰菊酯与联苯菊酯、三氟氯氰菊酯、水胺硫磷、久效磷、氰久合剂有交互抗性,甲氰菊酯还与螨蚧克有交互抗性;四螨嗪与三氯杀螨醇(RF=14.15倍)、齐螨素(RF=10.26倍)有交互抗性;螨嗪菊酯与双甲脒、氧乐菊酯有负交互抗性,RF值分别为0.85、0.71倍。

Resistance of Tetranychue uriticae Koch to several insecticides and their mixtures

The susceptible population of Tetranychus urticae Koch were collected from Lonicera chrysantha Turcz in Lanzhou Tulugou park and propagated on pot-cultured kidney bean seedling in the laboratory. The mite were selected with omethoate, fenpropathrin, clofentezine and mixture of fenpropathrin clofentezine (1:4) by spray method. The resistance factor (RF) of fenpropathrin of selected population was as high as 479.79-fold and that of the other three populations were 38.49, 67.26 and 26.75-fold respectively. From bioassay and enzyme activity measurements in vitro the results showed that the resistance population increased the activities of carboxyesterase, phos-phatase, GSH-s-aryltransferase and decreased the activity of acetylchorinesterase. Cross-resistance was determined for 15 pesticides to four selected resistance populations. Results revealed that resistance populations of omethoate and fenpropathrin showed cross-resistance to isocarbophos, monocro-tophos, bifenthrin, cyhalothrin and fenvalerate monocrotophos, and the latter also showed cross resistance to manjecke. Cross-resistance also appeared between clofentezine and dicofol and abamectin, but the fenpropathrin clofentezine mixture gave a negative cross resistance to amitraz and fenvalerate omethoate, the RF was 0.85 and 0.71-fold respectively. The cross-resistance of the four resistance population were not significantly different to each other except the mixture of fenpropathrin clofentezine to clofentezine, because the mixture contains clofentezine.