Airs Paul M, Kudrna Katherine E, Bartholomay Lyric C
Department of Pathobiological Sciences University of Wisconsin- Madison, Madison, WI, 53706, United States.
Department of Pathobiological Sciences University of Wisconsin- Madison, Madison, WI, 53706, United States.
Acta Trop. 2019 Mar;191:221-227. doi: 10.1016/j.actatropica.2019.01.005. Epub 2019 Jan 8.
Toxic Sugar Baits (TSBs) are an inexpensive and field-applicable approach to deliver a variety of insecticides to sugar-seeking mosquitoes. We reasoned that carbohydrate chemistry could alter the performance and efficacy of TSBs. In this study, the uptake, distribution, and survival of female Aedes aegypti provided with twelve different aqueous sugar meals was recorded. Sucrose, a standard control sugar used in mosquito rearing, is always diverted to the ventral diverticulum upon ingestion; but other sugars that might be found in nectar (e.g., maltose, mannose, and raffinose) dispersed to both the diverticulum and midgut. Sugar meals composed of arabinose, lactose, or cellobiose significantly reduced survival of Ae. aegypti compared to sucrose controls, with or without the addition of boric acid insecticide. The addition of arabinose to a TSB comprised of sucrose and boric acid reduced the survival of Ae. aegypti even when non-toxic sugar meals were readily available. In choice assays, Ae. aegypti were equally likely to feed on TSBs containing arabinose despite the toxicity associated with arabinose ingestion. TSBs typically contain broad spectrum insecticides; insecticidal RNA species that induce species-specific gene silencing are a potential alternative. To assess the potential of RNA delivery in a TSB, biodistribution of double-stranded RNA (dsRNA), was tracked after per os delivery in different sugar meals. None of the sugars tested facilitated uptake of dsRNA into midgut epithelia or other tissues. Overall, sourcing sugar baits from sources containing sugars with toxic properties may improve TSB efficacy in the field.
毒性糖饵（TSBs）是一种成本低廉且适用于野外的方法，可将多种杀虫剂传递给寻找糖分的蚊子。我们推测碳水化合物化学性质可能会改变毒性糖饵的性能和功效。在本研究中，记录了给雌性埃及伊蚊提供十二种不同糖水餐时的摄取、分布和存活情况。蔗糖是蚊子饲养中使用的标准对照糖，摄入后总会转移至腹侧憩室；但花蜜中可能存在的其他糖类（如麦芽糖、甘露糖和棉子糖）会分散至憩室和中肠。与蔗糖对照相比，由阿拉伯糖、乳糖或纤维二糖组成的糖水餐显著降低了埃及伊蚊的存活率，无论是否添加硼酸杀虫剂。在由蔗糖和硼酸组成的毒性糖饵中添加阿拉伯糖，即使有无毒糖水餐可供选择，也会降低埃及伊蚊的存活率。在选择试验中，尽管摄入阿拉伯糖具有毒性，但埃及伊蚊同样有可能取食含有阿拉伯糖的毒性糖饵。毒性糖饵通常含有广谱杀虫剂；诱导物种特异性基因沉默的杀虫RNA种类是一种潜在的替代物。为了评估在毒性糖饵中递送RNA的潜力，在经口投喂不同糖水餐后追踪双链RNA（dsRNA）的生物分布。所测试的糖类均未促进dsRNA摄取到中肠上皮或其他组织中。总体而言，从含有具有毒性的糖类来源获取糖饵可能会提高野外毒性糖饵的功效。
