Host Plant Phenology and Insect Speciation

9509125木材许多昆虫只以特定的寄主植物为食。这种专门化是如何产生的，它是否是物种形成的必要条件，以及它是否需要地理隔离，这些都有待讨论。当昆虫获得新的寄主植物时，了解其机制和后果是很重要的，原因有很多。寄主植物利用的变化发生在自然群落中，因此是了解昆虫-植物群落起源/结构和昆虫物种多样性地理格局的重要因素。如果一种新的寄主植物具有重要的商业价值，其结果往往是产生一种新的有害生物。在现有害虫物种的情况下，这种寄主植物的变化可能导致不同植物种群之间的遗传改变，这需要新的管理措施。因此，要了解自然和管理的植物群落，必须了解昆虫向新寄主植物转移的启动过程和最终后果。在这个提议中，将把来自单一种群的昆虫放在7个不同的环境中。每一种环境都由天然和新型寄主植物的不同组合组成。三种环境由新的和自然的寄主组成，可以确定当寄主物种之间存在潜在的自由昆虫运动时，是否会发生不同的寄主特化。其余的环境是研究当昆虫在自然和新寄主植物之间自由移动被禁止时寄主专业化的过程。该实验将在现场进行，利用28个大型屏蔽步入式房间。这七个环境中的每一个都将被复制四次。研究的变量将包括寄主植物物种对昆虫生活史的影响，虫卵孵化、交配和产卵的时间。在这些生活史的每个阶段，宿主对生存的不同影响将被确定。在这七个环境中，每个宿主之间的移动程度将通过标记昆虫来确定。

9509125 WOOD Many insect species are restricted to feed on specific host plants. How this specialization comes about, whether it is a requisite for speciation and whether it requires geographic isolation are open to debate. When insects acquire novel host plants it is important to understand the mechanisms and consequences, for a number of reasons. Changes in host plant usage occur in natural communities and thus are important factors in attempts to understand the origin / structuring of insect-plant communities and geographic patterns of insect species diversity. If a new host plant is commercially important, the result is often the creation of a new pest. In cases of existing pest species such host plant changes can lead to genetic alterations between populations on different plants that require new management practices. Thus to understand natural and managed plant communities the processes that initiate and the ultimate consequences of insect shifts to new host plants must be understood. In this proposal insects from a single population will be manipulated by placing them in seven different environments. Each environment consists of different combinations of natural and novel host plants. Three environments consist of novel and natural hosts which allows the determination of whether divergent host specialization can occur when there is potential free insect movement between host species. The remaining environments are to examine the process of host specialization when free insect movement between natural and novel host plants is prohibited. The experiment will be done in the field utilizing 28 large screened walk-in rooms. Each of the seven environments will be replicated four times. Variables to be examined will be host plant species effects on insect life history timing of egg hatch, mating, and egg deposition. At each of these life history stages differential host effects on survival will be determined. The extent of movement between hosts within each of the seven enviro nments will be determined using marked insects.