International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya; Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa.
International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya.
Acta Trop. 2021 Jan;213:105745. doi: 10.1016/j.actatropica.2020.105745. Epub 2020 Nov 6.
The riverine tsetse fly Glossina fuscipes fuscipes is a major vector of trypanosome pathogens causing African trypanosomiasis. This fly species uses a combination of olfactory and visual cues to locate its hosts. Previously, traps and targets baited with visual cues have been used in vector control, but the development of olfactory-based tools has been challenging. Recently, repellents have shown promise as olfactory-based tools in tsetse vector control. Here, we evaluated a three-component blend comprising 6-methyl-5-hepten-2-one, acetophenone and geranyl acetone (blend K), previously identified as a repellent for savannah tsetse flies in zebra skin odor, on G. f. fuscipes populations. Using a series of 6 × 6 randomized Latin square-designed experiments, G. f. fuscipes catches in biconical traps were monitored on four islands of Lake Victoria in western Kenya between July and September 2019, after the long rainy season. Traps were baited with blend K and individual components of this blend. The known tsetse repellent blend WRC (waterbuck repellent compounds) and trap alone were included as controls. Daily catch data in thirty-six replicate trials were analyzed using generalized linear model with negative binomial error structure using the package "MASS" in R. Treatment, day and site were set as predictor variables. Our results showed that, blend K significantly reduced G. f. fuscipes catches by 25.6% (P < 0.01) compared to the control trap alone but was not significantly different from WRC which reduced catches by 20.7% (P < 0.05). Of the individual compounds, geranyl acetone solely significantly reduced catches by 29.1% (P < 0.01) which did not differ from blend K or WRC. We conclude that geranyl acetone accounts for the repellent effect of blend K on the riverine tsetse fly, G. f. fuscipes, demonstrating the ecological importance of animal skin odors in the host-seeking behavior of medically-important tsetse fly vectors.
河流采采蝇 Glossina fuscipes fuscipes 是一种主要的媒介，可传播引起非洲锥虫病的锥虫病原体。这种蝇类使用嗅觉和视觉线索的组合来定位其宿主。以前，使用带有视觉线索的诱捕器和靶标已被用于病媒控制，但开发嗅觉工具具有挑战性。最近，驱避剂已显示出作为基于嗅觉的采采蝇病媒控制工具的潜力。在这里，我们评估了一种由 6-甲基-5-庚烯-2-酮、苯乙酮和香叶基丙酮组成的三组分混合物（混合物 K），该混合物先前在斑马皮气味中被鉴定为草原采采蝇的驱避剂，用于 G. f. fuscipes 种群。在 2019 年 7 月至 9 月期间，在肯尼亚西部维多利亚湖的四个岛屿上，使用一系列 6×6 随机拉丁方设计的实验，监测了 biconical 诱捕器中的 G. f. fuscipes 捕获量，这是在漫长的雨季之后。诱捕器用 K 混合物和该混合物的单个成分进行了诱饵处理。已知的采采蝇驱避剂混合物 WRC（水羚驱避化合物）和单独的诱捕器作为对照。在 R 语言的“MASS”包中使用具有负二项式误差结构的广义线性模型分析了 36 次重复试验的每日捕获数据。处理、天数和地点被设置为预测变量。我们的结果表明，与单独的诱捕器相比，K 混合物显著减少了 25.6%（P < 0.01）的 G. f. fuscipes 捕获量，但与减少了 20.7%（P < 0.05）的 WRC 混合物没有显著差异。在单个化合物中，香叶基丙酮单独显著减少了 29.1%（P < 0.01）的捕获量，与 K 混合物或 WRC 没有差异。我们得出结论，香叶基丙酮解释了 K 混合物对河流采采蝇 G. f. fuscipes 的驱避作用，这表明动物皮肤气味在医学上重要的采采蝇媒介寻找宿主的行为中具有生态重要性。
