Kojima Takeshi, Yamato Seiji, Kawamura Shinichi
Health & Crop Sciences Research Laboratory, Sumitomo Chemical Co., Ltd., 2-1 Takatsukasa 4-Chome, Takarazuka, Hyogo 665-8555, Japan.
Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
Insects. 2022 Jul 27;13(8):678. doi: 10.3390/insects13080678.
Pyrethrum is a botanical insecticide derived from pyrethrum flowers. Feeding deterrence caused by pyrethrum has been reported in several sucking insects; however, there is no account of the cause of deterrence-whether from a single component or the combination of six active ingredients, called pyrethrins. We determined the feeding deterrence of natural pyrethrins, their two main components (pyrethrins I and II), and pyrethroid insecticides on the blowfly, . In a dual-choice feeding assay that minimized tarsal contact with food sources but allowed feeding through proboscises, natural pyrethrins, synthetic pyrethrins I/II, and allethrin were observed to induce deterrence at a concentration 16 times lower than the lowest concentration at which the knockdown rate increased. Feeding bouts were interrupted by intensive grooming of the proboscis at the deterring concentration, but no such grooming was observed to occur while feeding on the unpalatable tastants-NaCl, quinine, and tartaric acid. The underlying mode of action for the feeding deterrence of pyrethrins at sub-lethal concentrations probably occurs on the fly oral gustatory system, while differing from that of unpalatable tastants. The potent feeding deterrence of pyrethrins may provide effective protection for pyrethrum plants by rapidly deterring insects from feeding, before insecticidal activities occur.
除虫菊是一种从除虫菊花中提取的植物性杀虫剂。已有报道称，除虫菊对几种刺吸式昆虫具有取食驱避作用；然而，关于驱避作用的原因尚无定论——是来自单一成分还是六种活性成分（称为除虫菊酯）的组合。我们测定了天然除虫菊酯、其两种主要成分（除虫菊酯 I 和 II）以及拟除虫菊酯类杀虫剂对家蝇的取食驱避作用。在一项双选取食试验中，尽量减少跗节与食物源的接触，但允许通过喙取食，结果发现，天然除虫菊酯、合成除虫菊酯 I/II 和丙烯菊酯在比击倒率开始增加的最低浓度低 16 倍的浓度下就能诱导驱避作用。在驱避浓度下，取食行为会因对喙的频繁梳理而中断，但在取食难吃的味觉剂（氯化钠、奎宁和酒石酸）时未观察到这种梳理行为。亚致死浓度下除虫菊酯取食驱避作用的潜在作用模式可能发生在家蝇的口腔味觉系统上，与难吃的味觉剂的作用模式不同。除虫菊酯强大的取食驱避作用可能通过在杀虫活性发生之前迅速阻止昆虫取食，为除虫菊植物提供有效的保护。
