桃小食心虫幼虫越冬前后对几种杀虫剂敏感性的差异

用药液浸渍法测定了桃小食心虫幼虫越冬前和越冬后对三唑磷、辛硫磷、马拉硫磷、毒死蜱、高效氯氟氰菊酯和阿维菌素等杀虫剂的敏感性差异.结果表明:越冬后幼虫对上述药剂的敏感性分别是越冬前幼虫的34.50、16.71、3.89、3.28、5.90和2.73倍.幼虫越冬后体内能源物质蛋白质、糖元和脂肪含量分别比越冬前降低17.10%、41.76%和30.08%;羧酸酯酶、酸性磷酸酯酶、碱性磷酸酯酶及谷胱甘肽-S-转移酶的活力分别比越冬前降低62.36%、53.47%、76.19%和80.60%;超氧化物歧化酶、过氧化氢酶、过氧化物酶等保护酶活力比越冬前分别降低18.77%、14.16%和64.02%;而幼虫体内多种农药的靶标酶乙酰胆碱酯酶活力的变化则相反,该酶在越冬后幼虫体内的活力是越冬前的1.41倍.表明越冬后幼虫对药剂敏感性的提高与体内能源物质含量、代谢酶、保护酶和靶标酶的活力变化有关.

Susceptibility and related physiological and biochemical mechanisms of Carposina niponensis Walsingham larvae on six insecticides before and after overwintering

The study with impregnating method showed that after overwintering, the susceptibility of Carposina niponensis larvae on triazophos, phoxim, chlorpyrifos, malathion, lambda-cyhalothrin and abamectin was 34.50, 16.71, 3.89, 3.28, 5.90 and 2.73 times as much as that before overwintering, the total protein, glycogen and fat contents and carboxylesterase, acid phosphatase, alkaline phosphatase, glutathione-S-transferase, superoxide dismutase, catalase and peroxidase activities in C. niponensis larvae were decreased by 17.10%, 41.76% and 30.08%, 62.36%, 53.47%, 76.19%, 80.60%, 18.77%, 14.16% and 64.02%, respectively, and the activity of acetylcholinesterase, the target enzyme of many insecticides, was 1.41 times as much as that before overwintering. It was suggested that the difference of the susceptibility was resulted from the changes in the contents of biochemical substances and the activities of metabolic enzymes, protective enzymes and target enzyme.