Dissertation Research: The Relative Roles of Host Quality and Enemy Free Space in Determining the Host Preferences of a Generalist Herbivore, Vanessa cardui

植物-昆虫相互作用研究的一个中心问题是 为什么草食性昆虫倾向于把它们的食物限制在 有限的主机范围。 拟议研究的目标是 通过比较通才来解决专业化的问题， 草食动物在几种可能的宿主上的表现， 寄主质量和天敌的攻击率。 初步调查显示瓦内萨 cardui的增长是穷人在其首选主机相对于其他 可用的主机，这表明主机质量相对较低 比其他生态因子更重要的是决定它的宿主 喜好 天敌的潜在作用 确定东道主的偏好已经有力地说明， 实验研究仍相对薄弱。 的 自然资源重要性的纬度梯度的可能性 敌人的建议，并将调查比较 在V. cardui的宿主偏好和攻击率的变化 在几个地方被天敌捕食 一种多面手食草动物 被选为这项研究，以获得一个清晰的看法， 草食动物的表现在各种主机之前， 食草动物有相当长的时间来适应它的宿主， 多个维度

A central question in the study of plant-insect interactions is why herbivorous insects tend to restrict their feeding to a limited range of hosts. The goal of the proposed research is to address this question of specialization by comparing a generalist herbivore's performance on several possible hosts in terms of both host quality and the rate of attack by natural enemies. Preliminary investigations have demonstrated that Vanessa cardui's growth is poor on its preferred host relative to other available hosts, suggesting that host quality is relatively less important than other ecological factors in determining its host preferences. The potential role of natural enemies in determining host preferences has been forcefully stated but remains relatively depauperate of experimental study. The possibility of a latitudinal gradient in importance of natural enemies is suggested and will be investigated by comparing variation in V. cardui's host preferences and the rate of attack by natural enemies in several sites. A generalist herbivore has been chosen for this study to obtain an unobscured view of the herbivore's performance on a variety of hosts before the herbivore has had significant time to adapt to its host in multiple dimensions.