Abo-Elghar Gamal E, El-Sheikh Anwar E, El-Sayed Ferial M, El-Maghraby Hamdi M, El-Zun Hesham M
Department of Pesticides, Faculty of Agriculture, Menoufiya University, Shebin El-Kom, Egypt.
Pest Manag Sci. 2004 Jan;60(1):95-102. doi: 10.1002/ps.783.
Three insect growth regulators (IGR), the chitin synthesis inhibitors (CSI) teflubenzuron and hexaflumuron and the juvenile hormone mimic (JHM) pyriproxyfen, as well as the organophosphate (OP) pirimiphos-methyl, were evaluated for their activity against the cowpea weevil, Callosobruchus maculatus (F), in cowpea seeds stored for up to 8 months post-treatment. The initial activity data showed that, based on LC50 level, teflubenzuron had strong ovicidal activity (LC50 = 0.056 mg kg(-1)) followed by pirimiphos-methyl (1.82 mg kg(-1)) and pyriproxyfen (91.9 mg kg(-1)). The residual activity data showed that none of the IGRs tested had strong activity when applied at 200 mg kg(-1) in reducing the oviposition rates of C maculatus at various storage intervals up to 8 months post-treatment. However, teflubenzuron reduced adult emergence (F1 progeny), achieving control ranging from 96.2% at 1 month to 94.3% at 8 months. Hexaflumuron showed a similar trend in its residual activity, ranging between 93.8% control at 1 month to 88.2% control at 8 months post-treatment. However, pyriproxyfen was more active than the CSIs tested and caused complete suppression (100% control) of adult emergence at all storage intervals. Unlike the IGRs tested, pirimiphos-methyl applied at 25 mg kg(-1) was more effective in reducing oviposition rates of C maculatus up to 8 months post-treatment. A strong reduction of adult emergence was also observed at various bimonthly intervals (98.6% control at 1 month to 91.6% control at 8 months post-treatment). The persistence of hexaflumuron and pirimiphos-methyl in cowpea seeds was also studied over a period of 8 months. The loss of hexaflumuron residue in treated cowpeas (200 mg kg(-1)) was very slow during the first month post-treatment (4.43%). At the end of 8 months, the residue level had declined significantly to 46.4% of the initial applied rate. The loss of pirimiphos-methyl residue in treated cowpeas (25 mg kg(-1)) was relatively high during the first month post-treatment (36.7%) and increased to 81.6% after 8 months.
评估了三种昆虫生长调节剂（IGR），即几丁质合成抑制剂（CSI）氟苯脲和六氟虫脲，以及保幼激素类似物（JHM）吡丙醚，还有有机磷酸酯（OP）甲基嘧啶磷，在处理后储存长达8个月的豇豆种子中对豇豆象（Callosobruchus maculatus (F)）的活性。初始活性数据表明，基于半数致死浓度（LC50）水平，氟苯脲具有很强的杀卵活性（LC50 = 0.056 mg kg⁻¹），其次是甲基嘧啶磷（1.82 mg kg⁻¹）和吡丙醚（91.9 mg kg⁻¹）。残留活性数据表明，在处理后长达8个月的不同储存期，以200 mg kg⁻¹的剂量施用时，所测试的IGR均没有很强的降低黄斑豆象产卵率的活性。然而，氟苯脲降低了成虫羽化率（F1代子代），在1个月时防治率达到96.2%，在8个月时达到94.3%。六氟虫脲在残留活性方面呈现类似趋势，处理后1个月时防治率为93.8%，8个月时为88.2%。然而，吡丙醚比所测试的CSI更具活性，在所有储存期均导致成虫羽化完全受到抑制（100%防治）。与所测试的IGR不同，以25 mg kg⁻¹的剂量施用甲基嘧啶磷在处理后长达8个月时，在降低黄斑豆象产卵率方面更有效。在不同的双月间隔期也观察到成虫羽化率大幅降低（处理后1个月时防治率为98.6%，8个月时为91.6%）。还研究了六氟虫脲和甲基嘧啶磷在豇豆种子中的残留情况，为期8个月。处理后的豇豆（200 mg kg⁻¹）中六氟虫脲残留量在处理后的第一个月损失非常缓慢（4.43%）。在8个月末，残留水平显著下降至初始施用量的46.4%。处理后的豇豆（25 mg kg⁻¹）中甲基嘧啶磷残留量在处理后的第一个月损失相对较高（36.7%），8个月后增加到81.6%。
