An Environmental Model for Developing Novel IPM Techniques for Control of Swede Midge in Brassicas

2020年，英国种植了27，420公顷的园艺芸苔属植物，为英国经济贡献了3. 02亿英镑（Defra园艺统计数据，2020年）。近年来，由于杀虫剂毒死蜱的损失，瑞典吸浆虫已成为英国芸苔生产的毁灭性威胁。幼虫喂养对花椰菜、西兰花和卷心菜等结球作物特别有威胁。由于蠓的存在，这些作物中的一些已经不可能有机地种植了。使用作物网覆盖物可以通过排除成虫来减少瑞典吸浆虫的损害，从而防止产卵，但需要进行研究以更有效地使用这些覆盖物并更好地了解作物风险，特别是因为它们经常被移除用于机械除草。目前的建议是依靠轮作和与以前受感染的作物保持距离，以防止第一代蠓成虫从土壤中越冬的幼虫和蛹中出现时定居。然而，在距离最近的芸苔作物20英里的田地里发现了虫害，这些田地以前7-8年没有种植芸苔。这种行为使得它很难开发新的控制策略，是值得研究的。该项目建议开发一个环境模型，利用GIS来了解景观和作物历史因素如何影响害虫压力的第一代和第二代瑞典吸浆虫。环境模型将有助于传统和有机芸苔种植者，以帮助作物保护决策和规划。该项目还将评估使用网状作物覆盖物对瑞典吸浆虫害虫的压力，同时考虑作物历史和景观特征，以确定吸浆虫是从当前芸苔属田地的土壤中出现还是从其他来源飞入作物。该项目的结果将有助于设计有效的新的农业生态控制策略的基础上瑞典吸浆虫的生物学和行为的知识，如陷阱种植或使用抑制覆盖作物。

There were 27,420 ha of horticultural brassicas grown in the UK in 2020, worth £302 million to the UK economy (Defra horticulture statistics, 2020). Swede midge has become a devastating threat to UK brassica production in recent years, since the loss of the insecticide chlorpyrifos. Larval feeding is particularly threatening to headed crops like cauliflower, broccoli and cabbage. It is not possible to grow some of these crops organically anymore because of the midge. Use of crop mesh covers can reduce swede midge damage by excluding the adult midges and thus prevent egg laying but research is needed to use these more effectively and better understand the crop risks, especially as they are often removed for mechanical weeding. Current advice is to rely on rotation and distance from previously infested crops to prevent colonisation of the first-generation midge adults when they emerge from overwintered larvae and pupae in the soil. However, infestations have been found in fields located 20 miles from the nearest brassica crop on land that had not previously grown brassicas for 7-8 years. This behaviour makes it difficult to develop novel control strategies and is worthy of research.This project proposes to develop an environmental model using GIS to understand how landscape and crop history factors influence pest pressure of the first and second generations of swede midge. The environmental model will be useful to conventional and organic brassica growers alike to help inform crop protection decision making and planning. The project will also assess swede midge pest pressure with the use of mesh crop covers, taking into account crop history and landscape features to determine whether the midges are emerging from the soil in the current brassica field or flying into the crop from another source. The results of this project will help to design effective novel agroecological control strategies based on knowledge of swede midge biology and behaviour, such as trap cropping or use of suppressive cover crops.