Optimising symbiont-mediated RNA interference as a control measure for Western Flower Thrips and Tomato Spotted Wilt Virus

目前的农业病虫害防治策略严重依赖化学农药。然而，没有安全的靶向化学杀虫剂；这些化学物质也会影响非目标有益昆虫物种，如授粉蜜蜂。申请者最近开发了一种新技术，共生体介导的RNA干扰(SMR)，可以在广泛的昆虫中应用。这项建议将扩大他们在应用SMR控制西花蓟马(WFT)种群方面的成功。WFT是蔬菜和观赏作物的主要害虫，它们以许多植物的叶子、花和花粉为食。它们作为一种入侵物种分布在全球，在过去50年里从美国西部传播开来。作为一种杀虫剂，SMR具有双重特异性，这意味着只应影响目标物种，而不应影响蜜蜂等有益物种。这项建议探讨了如何优化该技术以控制WFT的种群数量，以及是否可以扩展该技术以限制番茄斑点枯萎病毒的传播。这种植物病毒由WFT传播，可侵染84科1000多种植物，是所有植物病原体中寄主范围最广的之一；每年给全球农业造成的损失超过10亿美元。证明SMR可以防止昆虫传播病毒将是一项重要的概念验证，这将意味着该技术如何应用于其他环境，如限制登革热和寨卡病毒通过蚊子的传播。此外，研究方案将提供实验数据，以证明目标物种的特异性，例如，是否可能对蜜蜂产生任何有害影响，以及水平基因转移和抗药性的演变是否可能成为未来SMR技术田间应用的关注问题。

Current control strategies for agricultural insect pests are heavily reliant on chemical pesticides. However, there is no safe targeted chemical pesticide; these chemicals can also affect non-target beneficial insect species such as pollinating bees. The applicants have recently developed a new technology, symbiont-mediated RNA interference (SMR), that can be applied in a wide range of insects. This proposal will extend their success in applying SMR to control populations of Western Flower Thrips (WFT). WFT are a major pest of both vegetables and ornamental crops, and they feed on leaves, flowers, and pollen, of many plant species. They are globally distributed as an invasive species that has spread from western USA in the last 50 years. As a pesticide, SMR offers two-tier specificity, meaning that only the target species, and not beneficial species such as bees, should be affected. This proposal explores how the technology can be optimised for population control of WFT and whether it can be extended to limit transmission of Tomato Spotted Wilt Virus. This plant virus is transmitted by WFT and can infect over 1,000 species of plants in 84 families, giving it one of the broadest host ranges of any plant pathogen; it causes annual losses to agriculture worldwide of over $1 billion value. Demonstrating that SMR can prevent virus transmission by an insect will be an important proof-of-concept, with implications for how the technology could be applied in other contexts such as limiting the spread of Dengue and Zika viruses by mosquitoes. In addition, the research programme will provide experimental data to demonstrate target species specificity, for instance whether there could be any detrimental effects on honey bees, and whether horizontal gene transfer and the evolution of resistance could be concerns with respect to future field applications of the SMR technology.