The brown planthopper （BPH）, Nilaparvata lugens （Stal）, is one of the major pests of rice throughout Asia. Extensive use of insecticides for suppressing N. lugens has resulted in the development of insecticide res...The brown planthopper （BPH）, Nilaparvata lugens （Stal）, is one of the major pests of rice throughout Asia. Extensive use of insecticides for suppressing N. lugens has resulted in the development of insecticide resistance leading to frequent control failures in the field. The aim of the present study was to evaluate resistance in the field populations of N. lugens from major rice growing states of South India to various insecticides. We also determined the activity of detoxifying enzymes （esterases [ESTs], glutathione S- transferases [GSTs], and mixed-fimction oxidases [MFOs]）. Moderate levels of resistance were detected in the field populations to acephate, thiamethoxam and buprofezin （resistance factors 1.05-20.92 fold, 4.52-14.99 fold, and 1.00-18.09 fold, respectively） as compared with susceptible strain while there were low levels of resistance to imidacloprid （resistance factor 1.23-6.70 fold） and complete sensitivity to etofenoprox （resistance factor 1.05- 1.66 fold）. EST activities in the field populations were 1.06 to 3.09 times higher than the susceptible strain while for GST and MFO the ratios varied from 1.29 to 3.41 and 1.03 to 1.76, respectively. The EST activity was found to be correlated to acephate resistance （r = 0.999, P ≥ 0.001）. The high selection pressure of organophosphate, neonicotinoid, and insect growth regulator （IGR） in the field is likely to be contributing for resistance in BPH to multiple insecticides, leading to control failures. The results obtained will be beneficial to IPM recommendations for the use of effective insecticides against BPH.展开更多
甲氧虫酰肼是昆虫蜕皮激素类似物,能干扰昆虫新表皮的形成。为了研究甲氧虫酰肼对舞毒蛾(Ly-mantria dispar)杀虫活性以及与其代谢相关酶的活性,采用叶片药膜法测定了甲氧虫酰肼对舞毒蛾2、3龄幼虫毒力及对其多功能氧化酶(MFOs)和羧基...甲氧虫酰肼是昆虫蜕皮激素类似物,能干扰昆虫新表皮的形成。为了研究甲氧虫酰肼对舞毒蛾(Ly-mantria dispar)杀虫活性以及与其代谢相关酶的活性,采用叶片药膜法测定了甲氧虫酰肼对舞毒蛾2、3龄幼虫毒力及对其多功能氧化酶(MFOs)和羧基酰胺酶活性的影响。结果表明:甲氧虫酰肼对舞毒蛾2、3龄幼虫,48 h LC50分别为14.004、24.105 mol.L-1;48 h LC5分别为1.573、2.090 mol.L-1;48 h LC20分别为4.575、6.898 mol.L-1。用甲氧虫酰肼亚致死剂量48 h LC5和48 h LC20处理舞毒蛾幼虫后,2龄幼虫MFOs活性表现出先激活再抑制再激活;3龄幼虫则表现出先抑制再激活再抑制的作用;2～3龄幼虫羧基酰胺酶活性均表现出先激活再抑制再激活再抑制。可见,甲氧虫酰肼作为非甾醇类蜕皮激素竞争物中的新型化合物,对舞毒蛾幼虫有较高的生物活性,对舞毒蛾幼虫体内MFOs和羧基酰胺酶活性具有明显干扰作用。展开更多
文摘The brown planthopper （BPH）, Nilaparvata lugens （Stal）, is one of the major pests of rice throughout Asia. Extensive use of insecticides for suppressing N. lugens has resulted in the development of insecticide resistance leading to frequent control failures in the field. The aim of the present study was to evaluate resistance in the field populations of N. lugens from major rice growing states of South India to various insecticides. We also determined the activity of detoxifying enzymes （esterases [ESTs], glutathione S- transferases [GSTs], and mixed-fimction oxidases [MFOs]）. Moderate levels of resistance were detected in the field populations to acephate, thiamethoxam and buprofezin （resistance factors 1.05-20.92 fold, 4.52-14.99 fold, and 1.00-18.09 fold, respectively） as compared with susceptible strain while there were low levels of resistance to imidacloprid （resistance factor 1.23-6.70 fold） and complete sensitivity to etofenoprox （resistance factor 1.05- 1.66 fold）. EST activities in the field populations were 1.06 to 3.09 times higher than the susceptible strain while for GST and MFO the ratios varied from 1.29 to 3.41 and 1.03 to 1.76, respectively. The EST activity was found to be correlated to acephate resistance （r = 0.999, P ≥ 0.001）. The high selection pressure of organophosphate, neonicotinoid, and insect growth regulator （IGR） in the field is likely to be contributing for resistance in BPH to multiple insecticides, leading to control failures. The results obtained will be beneficial to IPM recommendations for the use of effective insecticides against BPH.
文摘甲氧虫酰肼是昆虫蜕皮激素类似物,能干扰昆虫新表皮的形成。为了研究甲氧虫酰肼对舞毒蛾(Ly-mantria dispar)杀虫活性以及与其代谢相关酶的活性,采用叶片药膜法测定了甲氧虫酰肼对舞毒蛾2、3龄幼虫毒力及对其多功能氧化酶(MFOs)和羧基酰胺酶活性的影响。结果表明:甲氧虫酰肼对舞毒蛾2、3龄幼虫,48 h LC50分别为14.004、24.105 mol.L-1;48 h LC5分别为1.573、2.090 mol.L-1;48 h LC20分别为4.575、6.898 mol.L-1。用甲氧虫酰肼亚致死剂量48 h LC5和48 h LC20处理舞毒蛾幼虫后,2龄幼虫MFOs活性表现出先激活再抑制再激活;3龄幼虫则表现出先抑制再激活再抑制的作用;2～3龄幼虫羧基酰胺酶活性均表现出先激活再抑制再激活再抑制。可见,甲氧虫酰肼作为非甾醇类蜕皮激素竞争物中的新型化合物,对舞毒蛾幼虫有较高的生物活性,对舞毒蛾幼虫体内MFOs和羧基酰胺酶活性具有明显干扰作用。
