Gontijo Pablo C, Moscardini Valéria F, Michaud J P, Carvalho Geraldo A
Department of Entomology, Federal University of Lavras, Lavras, Minas Gerais, Brazil; Department of Entomology, Kansas State University, Agricultural Research Center-Hays, Hays, Kansas, USA.
Pest Manag Sci. 2015 Apr;71(4):515-22. doi: 10.1002/ps.3798. Epub 2014 May 12.
Systemic insecticides used as seed treatments are generally considered to be safe for natural enemies. However, predatory insects may feed directly on plants or use plant products to supplement their diet. This study examined whether chlorantraniliprole or thiamethoxam might negatively impact Orius insidiosus (Say) (Hemiptera: Anthocoridae) when bugs utilize sunflowers grown from treated seed.
When eggs of O. insidiosus were laid in the stems of treated sunflower seedlings (two-leaf stage), thiamethoxam reduced egg viability and the longevity of females hatching from these eggs, whereas chlorantraniliprole reduced female survival. Thiamethoxam, but not chlorantraniliprole, reduced female fertility in six-leaf-stage plants. Nymphs exposed to thiamethoxam-treated seedlings had reduced survival, delayed development and reduced fecundity as adults, relative to other treatments, whereas chlorantraniliprole delayed oviposition. Nymphs exposed to six-leaf-stage plants did not differ from controls in either treatment. Adults exposed to treated plants expressed no significant differences among treatments for any parameter evaluated for either plant growth stage.
Thiamethoxam treatment on sunflower seeds caused lethal and sublethal effects on O. insidiosus, whereas chlorantraniliprole was not lethal to any life stage, although sublethal effects were evident. The nymphal stage was most susceptible, and insecticidal toxicity diminished with plant development.
用作种子处理剂的内吸性杀虫剂通常被认为对天敌是安全的。然而，捕食性昆虫可能直接取食植物或利用植物产品补充其食物。本研究调查了当臭虫取食经处理种子种植的向日葵时，氯虫苯甲酰胺或噻虫嗪是否会对暗黑赤眼蜂（Say）（半翅目：花蝽科）产生负面影响。
当暗黑赤眼蜂的卵产在经处理的向日葵幼苗（二叶期）茎中时，噻虫嗪降低了卵的活力以及从这些卵孵化出的雌虫寿命，而氯虫苯甲酰胺降低了雌虫存活率。噻虫嗪而非氯虫苯甲酰胺降低了六叶期植株中雌虫的繁殖力。与其他处理相比，接触经噻虫嗪处理幼苗的若虫存活率降低、发育延迟且成虫期繁殖力降低，而氯虫苯甲酰胺延迟了产卵。接触六叶期植株的若虫在两种处理中与对照均无差异。对于任一植物生长阶段评估的任何参数，接触经处理植株的成虫在各处理间均未表现出显著差异。
向日葵种子上的噻虫嗪处理对暗黑赤眼蜂产生了致死和亚致死效应，而氯虫苯甲酰胺对任何生命阶段均无致死性，尽管亚致死效应明显。若虫期最敏感，且杀虫毒性随植物发育而降低。
