Multiple stressor effects in biological pest control; improving efficacy in challenging environments

迫切需要在农业方面发展新的创新，使作物的种植不损害环境。目前，农民严重依赖合成化学农药来保护作物免受植物病虫害的侵害，但过度使用可能会损害野生动物和环境。生物农药是一种“环境友好”的作物保护剂，基于天然产物或活生物体。它们旨在用于病虫害综合管理（IPM）系统，在该系统中，不同的作物保护工具一起使用，以减少对化学农药的过度依赖。虽然生物农药的使用正在迅速增加，但仍然缺乏关于它们如何与其他作物保护方法相互作用以及这如何影响虫害控制水平的基本知识。本博士项目涉及基于昆虫病原微生物的生物农药新知识开发研究。主要重点是利用生态毒理学建模方法表征和更好地了解它们与化学品和其他生物农药的相互作用。这将包括研究微生物生物农药和农药在种植系统中不同环境条件下如何相互作用（例如Hesketh & Hails， 2015）。因此，该项目的总体目标是；-确定在何处及如何将病原体与化学除害剂/杀菌剂结合使用，以取得最大及可靠的防治虫鼠效果。-了解不同气候条件/环境的额外压力因素如何影响病原体/化学物质之间相互作用的变化，以及这对害虫控制的影响。该项目将包括广泛的实验实验室和实地组成部分以及统计分析方面的培训。实验工作将主要集中在昆虫病原真菌球孢白僵菌（几种生物防治产品的基础）和寄主昆虫，如蚜虫和白蝇，作为示范作物的西红柿。实验将从最初的实验室，前1-2年在小的微观世界中进行控制实验，到3-4年在温室中进行越来越复杂的实验。这些实验旨在提高对微生物病原体/化学物质组合之间的积极（加性和协同）和消极（拮抗）生态相互作用的理解和检测。使用基于MIXtox模型的新颖实验设计和数据分析，将进一步提高描述微生物昆虫病原体如何相互作用的能力（Jonker等人，1995年）。这将改进目前病原体/毒物混合物影响的统计分析方法

There is an urgent need to develop new innovations in agriculture that enable crops to be grown without harming the environment. At the moment, farmers are heavily reliant on synthetic chemical pesticides to protect crops against plant pests and diseases, but excessive use can be damaging to wildlife and the environment. Biopesticides are an "environmentally friendly" crop protection agent, based on natural products or living organisms. They are intended for use in Integrated Pest Management (IPM) systems, in which different crop protection tools are used together to reduce over reliance on chemical pesticides. Whilst the use of biopesticides is increasing rapidly, there remains a lack of basic knowledge about how they interact with other crop protection methods and how this affects levels of pest control. This PhD project concerns research to develop new knowledge on biopesticides based on insect pathogenic microorganisms. The main focus is to characterize and to better understand their interactions with chemicals and other biopesticides using an eco-toxicological modeling approach. This will include studies of how microbial biopesticides and pesticides interact under different environmental conditions in cropping systems (e.g. Hesketh & Hails, 2015). The overarching aims of this project are therefore; - to identify where, and how, pathogens can be combined with chemical pesticides/fungicides for maximum and reliable effects in terms of pest control. - to understand how impacts of additional stressors of varying climatic conditions/environments will mediate change in interactions between pathogens/chemicals and the implications this has for pest control. The project will have extensive experimental laboratory and field components as well as training in statistical analysis. The experimental work will primarily focus on the entomopathogenic fungus, Beauveria bassiana (the basis of several biocontrol products) and host insects such as aphids and whitefly in tomatoes as an exemplar crop. Experiments will progress from initial laboratory, controlled experiments in the first 1-2 years with small microcosms, with increasingly complex experiments in glasshouses in years 3-4. These experiments will be designed to improve understanding and detect positive (additive and synergistic) and negative (antagonistic) ecological interactions between microbial pathogens/chemicals in combination. The ability to describe how microbial insect pathogens interact will be furthered by using novel experimental designs and data analysis based on the MIXtox models (Jonker et al., 1995). This will improve current methods of statistical analysis of the effects of mixtures of pathogens/toxicants