Mechanisms of tritrophic effects of plant chemistry on a parasitoid

植物化学对寄生蜂Paul Ode1和May Berenbaum的三营养作用机制21北达科他州州立大学2伊利诺伊大学香槟分校植物化学不仅对草食动物有影响，而且对这些草食动物的天敌也有影响。虽然植物化学对天敌寄主寻找和接受行为的影响在许多系统中都得到了很好的研究，但关于植物化学对其他适合度相关因素的影响以及天敌如何应对植物化学的负面影响的研究相对较少。在植物和食草动物之间的选择性相互作用已被特别好地研究的系统中，寄生黄蜂是主要的天敌。由野生防风草属植物Pastinaca sativa生产的呋喃香豆素选择了防风草属网虫Depressaria Pastinacella的解毒能力，Depressaria Pastinacella是野生防风草属的专业草食动物。反过来，网虫的食草性选择了野生防风草对呋喃香豆素的抗性。这种三营养系统原产于欧洲，并已被引入北美西部；野生防风草属和防风草属网虫遍布北美中西部，但实际上是无寄生蜂的。该项目的中心目标是研究野生防风草呋喃香豆素对珊瑚生长和繁殖的影响。美国西部种群中防风草属植物的呋喃香豆素图谱及其与苏萨雷斯适合度指标的相关性将被记录在案。实验室研究，操纵人工饲料中的花椒毒素浓度，将直接检验呋喃香豆素对刺参适合性措施的影响。其他实验将检查苏萨雷斯毛虫在其网虫宿主中遇到的呋喃香豆素水平，以及它们对任何遇到的呋喃香豆素的解毒能力。最后，我们将研究呋喃香豆素的变异对苏萨雷斯的生殖决策的影响。美国中西部相对无寄生蜂种群的存在，以及欧洲和美国西部严重寄生种群的存在，使得寄生蜂对网虫解毒能力和植物化学的影响得以比较。研究寄主植物化学对天敌的生理效应将有助于更全面地了解营养关系是如何发挥作用的。

Mechanisms of tritrophic effects of plant chemistry on a parasitoidPaul Ode1 and May Berenbaum21North Dakota State University2University of Illinois at Urbana-ChampaignPlant chemistry is well known to have impacts not only on herbivores, but also on natural enemies of these herbivores. While the effects of plant chemistry on host finding and acceptance behavior of natural enemies is well studied in many systems, comparatively little is known about effects of plant chemistry on other fitness correlates and how natural enemies are able to cope with negative effects of plant chemistry. The parasitic wasp, Copidosoma sosares, is the predominant natural enemy in a system where the selective interactions between plant and herbivore have been particularly well studied. Furanocoumarin production by wild parsnip plants, Pastinaca sativa, selects for detoxification capabilities of the parsnip webworm, Depressaria pastinacella, a specialist herbivore of the wild parsnip. In turn, herbivory by the webworms selects for furanocoumarin-based resistance by wild parsnips. This tritrophic system is native to Europe and has been introduced to western North America; wild parsnips and parsnip webworms are found throughout Midwestern North America, but are effectively parasitoid-free. The central goal of this project is to examine the impacts of wild parsnip furanocoumarins on growth and reproduction of Copidosoma sosares. Furanocoumarin profiles of parsnip plants and their correlation with C. sosares fitness measures in western US populations will be documented. Laboratory studies, manipulating xanthotoxin concentrations in artificial diets, will directly examine the effect of furanocoumarins on C. sosares fitness measures. Other experiments will examine levels of furanocoumarins encountered by C. sosares in their webworm hosts as well as their ability to detoxify any encountered furanocoumarins. Finally, the effects of furanocoumarin variation on reproductive decisions made by C. sosares will be examined. The existence of relatively parasitoid free populations in the Midwestern US and heavily parasitized European and western US populations allows comparison of parasitoid effects on webworm detoxification abilities as well as plant chemistry. Studying the physiological effects of host plant chemistry on natural enemies will allow for a more complete understanding of how trophic relationships function.