Lawson Blythe E, McDermott Emily G
University of Arkansas, Department of Entomology and Plant Pathology, Fayetteville, AR 72704, USA.
Acta Trop. 2024 Nov;259:107358. doi: 10.1016/j.actatropica.2024.107358. Epub 2024 Aug 22.
Fly control for any species is most effectively implemented in the immature stages when insects can be eliminated before emerging as adults capable of transmitting pathogens or becoming nuisance pests. Yet a limited number of insecticide classes are available for treating larval development sites for dipteran pest species. The most recently introduced class of insecticides in the United States (US) is the isoxazolines, including fluralaner. In the US, fluralaner is currently exclusively labeled for use against ectoparasites in companion animals. However, research has shown that it has a wider effective target range beyond ectoparasites and could be developed as an insecticide for vector control. Here we tested a novel, proprietary, yeast microencapsulated (YME) formulation of fluralaner against the larvae of three pest species: Musca domestica L. (Diptera: Muscidae), Aedes albopictus Skuse (Diptera: Culicidae), and Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae). These species all naturally consume microorganisms as larvae, including yeasts. Fluralaner was successfully microencapsulated in Saccharomyces cerevisiae yeast. YME fluralaner was reconstituted in water at concentrations of 0.00001-0.1 mg/mL (Aedes and Culicoides) or 1-50 mg/mL (Musca) for use in dose-response assays. For each species, the LC at 24 h was estimated using probit analyses. YME fluralaner was highly effective against all species tested (Ae. albopictus LC = 0.000077 mg/mL; C. sonorensis LC = 0.00067 mg/mL; M. domestica LC = 2.58 mg/mL). Additionally, laboratory assays were conducted to determine product reapplication rates using LC rates. Reapplication rates to maintain <50 % emergence were five weeks (Ae. albopictus) and greater than eight weeks (C. sonorensis). The results presented here indicate YME fluralaner is a promising candidate for controlling larval insects that naturally feed on detritus, thereby bypassing cuticular penetration barriers and safely delivering the active ingredient to the target species.
对于任何物种，在昆虫处于未成熟阶段时实施蝇类控制最为有效，因为此时昆虫在发育为能够传播病原体或成为有害害虫的成虫之前就可以被消灭。然而，可用于处理双翅目害虫幼虫发育场所的杀虫剂种类有限。美国最近引入的一类杀虫剂是异恶唑啉类，包括氟虫腈。在美国，氟虫腈目前仅被标记用于防治伴侣动物的体外寄生虫。然而，研究表明，它的有效靶标范围比体外寄生虫更广，可开发为用于病媒控制的杀虫剂。在此，我们测试了一种新型的、专有的、酵母微囊化（YME）的氟虫腈制剂对三种害虫幼虫的效果：家蝇（双翅目：蝇科）、白纹伊蚊（双翅目：蚊科）和索诺拉库蠓（双翅目：蠓科）。这些物种在幼虫阶段都自然摄食微生物，包括酵母。氟虫腈成功地微囊化在酿酒酵母中。YME氟虫腈在水中以0.00001 - 0.1毫克/毫升（伊蚊和库蠓）或1 - 50毫克/毫升（家蝇）的浓度复溶，用于剂量反应试验。对于每个物种，使用概率分析估计24小时的半数致死浓度（LC）。YME氟虫腈对所有测试物种都非常有效（白纹伊蚊LC = 0.000077毫克/毫升；索诺拉库蠓LC = 0.00067毫克/毫升；家蝇LC = 2.58毫克/毫升）。此外，进行了实验室试验以使用LC率确定产品重新施药率。保持羽化率低于50%的重新施药率分别为五周（白纹伊蚊）和超过八周（索诺拉库蠓）。此处呈现的结果表明，YME氟虫腈是控制以腐殖质为食的幼虫昆虫的一个有前景的候选产品，从而绕过表皮渗透障碍并将活性成分安全地递送至目标物种。
