Effects of 3-trophic-level Interactions on Sex Ratios of an Herbivore and Parasite

能够控制潜在害虫种群的最重要的一类生物是寄生在寄主的卵、幼虫或蛹上的寄生蜂。这些寄生蜂是传统生物防治的主要手段，在影响农业和减少全球农药使用方面具有巨大潜力。寄生蜂有着丰富的生活史和控制后代性别比例的独特能力。性别比例偏差对黄蜂种群的人口学特征及其与其他黄蜂物种的比较和调节宿主种群的能力具有重要影响。本研究涉及建立一种寄生在小菜蛾上的寄生蜂模型，小菜蛾是世界范围内十字花科作物（卷心菜、花椰菜等）的害虫。研究了植物质量对小菜蛾幼虫质量的影响，以及小菜蛾幼虫质量对小菜蛾种群分布的影响，特别是对小菜蛾性别比例偏态的影响。本研究的挑战是获得一个现实的模型，该模型集成了与3营养级生态相互作用中性别比例偏倚相关的遗传和环境因素，并使用该模型帮助解释从现场和实验室实验中获得的数据。研究结果对推广小菜蛾的生物防治具有重要意义。//

The most important group of organisms able to control potential insect pest populations are parasitic wasps that parasitize the eggs, larvae, or pupae of their host. These parasitic wasps are the mainstay of classical biological control which has enormous potential to impact agriculture and reduce the use of pesticides worldwide. Parasitic wasps have a vast array of life histories and a unique ability to control the sex ratio of their progeny. Sex ratio biasing has a critical impact on the demography of wasp populations and their ability to compare with other wasp species and regulate host populations. This study involves developing a model of a parasitic wasp Diadegma insulare on diamondback moth which is a pest in cruciferous crops (cabbage, cauliflower,etc.) world wide. The study focuses on the influence of the quality of plants on the quality of diamondback moth larvae and how the quality of these larvae influences the demography of Diadegma, especially in terms of sex ratio biasing. The challenge of the study is to obtain a realistic model that integrates genetic and environmental components associated with sex ratio biasing in a 3- trophic level ecological interaction, and to use the model to help interpret data obtained from field and laboratory experiments. The knowledge gained could help in promoting biological control of diamondback moth.//