Sunamura Eiriki, Tamura Shigeaki, Taki Hisatomo, Sato Hiroki, Shoda-Kagaya Etsuko, Urano Tadahisa
Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba, Ibaraki 305-8687, Japan.
Kansai Research Center, Forestry and Forest Products Research Institute, Nagaikyutaroh 68, Momoyama-cho, Fushimi-ku, Kyoto 612-0855, Japan.
Insects. 2021 Jun 29;12(7):592. doi: 10.3390/insects12070592.
In recent years, insecticide trunk injection was put into practical use for controlling wood boring pests. However, few studies have investigated the dose-response relationships between insecticides and wood-boring pests in detail. This study used two commercial formulations of the neonicotinoid insecticides thiamethoxam and dinotefuran and investigated their dose-response relationships with invasive wood borer (Coleoptera: Cerambycidae) larvae. Neonates and late instar larvae were reared with an artificial diet containing different insecticide concentrations (0.01-100 ppm) in the laboratory, and their diet excavation activity, survival rate, and weight change were recorded. Diet excavation immediately dropped in larvae exposed to high concentrations of thiamethoxam or dinotefuran (≥1 ppm in neonates and ≥10 ppm in late instar larvae). The weight and survival rate gradually declined over 12 weeks in late instar larvae. These results suggest that the two neonicotinoids intoxicate and debilitate larvae gradually to death. In practical use, rapid suppression of wood boring damage can be expected by trunk injection of neonicotinoid insecticides. However, a relatively long-term retention of the insecticides may be required to kill large larvae. Neonates may be controlled with lower insecticide dosage and shorter exposure than larger larvae.
近年来，树干注射杀虫剂已被实际用于防治蛀干害虫。然而，很少有研究详细调查杀虫剂与蛀干害虫之间的剂量反应关系。本研究使用了两种新烟碱类杀虫剂噻虫嗪和呋虫胺的商业制剂，并研究了它们与入侵性蛀干害虫（鞘翅目：天牛科）幼虫的剂量反应关系。在实验室中，用含有不同杀虫剂浓度（0.01 - 100 ppm）的人工饲料饲养初孵幼虫和大龄幼虫，并记录它们的饲料挖掘活动、存活率和体重变化。暴露于高浓度噻虫嗪或呋虫胺（初孵幼虫≥1 ppm，大龄幼虫≥10 ppm）的幼虫，其饲料挖掘活动立即下降。大龄幼虫的体重和存活率在12周内逐渐下降。这些结果表明，这两种新烟碱类杀虫剂会逐渐使幼虫中毒并衰弱直至死亡。在实际应用中，通过树干注射新烟碱类杀虫剂有望迅速抑制蛀干危害。然而，可能需要较长时间保留杀虫剂才能杀死大龄幼虫。与大龄幼虫相比，初孵幼虫可能用较低剂量的杀虫剂和较短的暴露时间就能得到控制。
