Hewa-Kapuge Swarna, McDougall Sandra, Hoffmann Ary A
Centre for Environmental Stress and Adaptation Research, La Trobe University, Bundoora, Victoria 3086, Australia.
J Econ Entomol. 2003 Aug;96(4):1083-90. doi: 10.1093/jee/96.4.1083.
Trichogramma nr. brassicae is a common egg parasitoid of Helicoverpa species in Australian processing tomatoes, but its effectiveness can be severely curtailed by insecticide applications. To identify insecticides that are potentially compatible with this species, the effects of seven insecticides, including newly introduced compounds and a surfactant, were screened in laboratory and glasshouse assays for their toxicity to the wasps. Assays involved direct applications on adults, residual effects on adults, and applications on life stages still inside the host. Methoxyfenozide and indoxacarb were not toxic to Trichogramma in any assay when applied at field rates. Naled and chlorfenapyr caused 100% mortality when directly applied to adults, and 95% mortality when adults were exposed to residues of these chemicals within 24 h of application. The effects of naled residues were short lived (<48 h). Naled and chlorfenapyr were also toxic when applied to Trichogramma developing inside host eggs, reducing emergence of adults by >25%. Imidacloprid, emamectin, and tau-fluvalinate were toxic in some experiments; they caused >97% mortality in adults 1 h after direct application and in residue assays they caused 23-64% mortality during the first 24 h. In field trials, methoxyfenozide had no harmful effects on emergence from sprayed parasitized eggs, whereas indoxacarb had a small impact (<8%) on emergence. Methoxyfenozide and indoxacarb are potentially suitable for inclusion in integrated pest management strategies for management of Helicoverpa because they do not influence adult survival or development of immature stages, whereas other chemicals need to be treated cautiously.
甘蓝夜蛾赤眼蜂是澳大利亚加工番茄中棉铃虫属害虫常见的卵寄生蜂，但其有效性会因杀虫剂的使用而受到严重影响。为了确定可能与该物种兼容的杀虫剂，在实验室和温室试验中筛选了七种杀虫剂（包括新引入的化合物和一种表面活性剂）对该黄蜂的毒性。试验包括直接施用于成虫、对成虫的残留影响以及对仍在寄主体内的发育阶段的施用。甲氧虫酰肼和茚虫威以田间使用剂量施用时，在任何试验中对甘蓝夜蛾赤眼蜂均无毒害。敌百虫和氯虫苯甲酰胺直接施用于成虫时导致100%死亡率，成虫在施药后24小时内接触这些化学物质的残留时死亡率为95%。敌百虫残留的影响持续时间较短（<48小时）。敌百虫和氯虫苯甲酰胺施用于寄主体内发育的甘蓝夜蛾赤眼蜂时也具有毒性，使成虫羽化率降低>25%。吡虫啉、甲氨基阿维菌素苯甲酸盐和高效氯氟氰菊酯在一些实验中具有毒性；直接施药1小时后成虫死亡率>97%，在残留试验中，在前24小时内死亡率为23 - 64%。在田间试验中，甲氧虫酰肼对喷洒过的寄生卵的羽化没有有害影响，而茚虫威对羽化有较小影响（<8%）。甲氧虫酰肼和茚虫威可能适合纳入棉铃虫综合害虫管理策略，因为它们不影响成虫存活或未成熟阶段的发育，而其他化学物质需要谨慎对待。
