New approaches to aphid control in strawberries combining botanicals with natural enemies'

蚜虫继续侵扰英国草莓，并造成广泛的损失，通过从植物中去除营养物质，传播病毒以及用排泄的蜜露扭曲和污染水果和叶子。虽然有几个物种攻击作物，但近年来马铃薯蚜虫（Macrosiphum euphorphium）对种植者来说是最大的问题，特别是在早春。批准用于蚜虫控制的杀虫剂要么在功效上不一致，要么对用于控制蚜虫和其他昆虫和螨类害虫的生物制剂产生负面影响。此外，另一种重要的草莓蚜虫害虫（棉花-甜瓜蚜虫，棉蚜）也出现了抗药性，进一步减少了有效的防治办法。这些问题，再加上最近和未来可能的农药退出，使传统杀虫剂的依赖不可持续的未来控制蚜虫。在这个项目中，学生将测试新的植物衍生化合物与证明杀虫活性。这些产品（包括在AHDB MOPS项目中显示出非常有希望的杀蚜活性的两种产品）已被选择用于进一步深入研究，因为它们通过不太可能导致抗性问题的机制起作用，并且初步测试表明对天敌没有残留毒性。在初步的生物测定比较选定的植物衍生化合物对马铃薯和棉花-甜瓜蚜虫的杀虫活性后，学生将探索它们的作用模式，特别是对昆虫的行为影响。除了对昆虫的直接影响外，这些化合物还具有作为植物自然防御过程诱导剂的潜力，学生还将研究这种可能的作用模式。还将探讨它们对蚜虫天敌（特别是拟寄生虫）的生物学和行为的影响。

Aphids continue to infest UK strawberries and cause extensive losses, by removing nutrients from plants, vectoring viruses as well as distorting and contaminating fruits and foliage with their excreted honeydew. While several species attack the crop, the potato aphid (Macrosiphum euphorbiae) has in recent years been the most problematic for growers, particularly in early spring. The insecticides that are approved for aphid control are either inconsistent in their efficacy or have a negative impact on the biologicals that are introduced to control aphids and other insect and mite pests. In addition, insecticide resistance has evolved in another important aphid pest of strawberries (cotton-melon aphid, Aphis gossypii), further reducing effective control options. These problems, combined with recent and likely future withdrawals of pesticides, make reliance on conventional insecticides unsustainable for future control of aphids.In this project, the student will test new plant-derived compounds with demonstrated insecticidal activity. These products (including two that showed very promising aphicidal activity in the AHDB MOPS project) have been selected for further in-depth investigation because they act via mechanisms that are unlikely to lead to resistance problems, and preliminary tests have indicated no residual toxicity to natural enemies. Following initial bioassays to compare the insecticidal activities of selected plant-derived compounds against potato and cotton-melon aphids, the student will explore their modes of action, and particularly behavioural effects on the insects. In addition to their direct effects on insects, these compounds also have potential as elicitors of plant natural defence processes, and the student will also investigate this possible mode of action. Their effects on the biology and behaviour of aphid natural enemies (particularly parasitoids) will also be explored.