Collaborative Research: Molecular Systematics of Drosophila Repleta Group Species

昆虫群所使用的寄主植物的范围可以很广，也可以很窄，包括寄主植物的特异性或对单一寄主的限制。绝大多数昆虫构成了所有动物物种的绝大多数，在其生命周期的某些部分以植物为食或作为繁殖场所，因此了解昆虫成为寄主专家或通才的原因是很重要的。寄主利用模式可能是解释昆虫类群多样化的重要因素。寄主植物的特定方面可能限制或增加昆虫物种可以利用的寄主数量。经过很长一段时间的间隔，这可能会产生具有共同寄主亲和力的昆虫物种的相关群体。该奖项支持的研究项目将使用DNA序列数据相似性模式来研究mulleri物种复合体（昆虫：双翅目：果蝇科）中40多个物种之间的遗传亲缘程度。确定的物种关系模式将与自然界中这些物种的宿主使用进行比较。在这个复杂的两个物种群中，每个有三个物种，将更详细地研究DNA序列数据中种群水平变化的证据。本研究的果蝇在仙人掌上繁殖，其幼虫以仙人掌寄主植物为食。有一个明显的寄主转移，一些物种以仙人掌属为食，其成员很容易通过桨状部分识别，到其他生长形式为柱状或桶状的仙人掌。了解果蝇物种之间的关系，将有助于确定仙人掌类型之间发生这种转变的次数。该奖项将提供关于一组专门以仙人掌为食的苍蝇的生物多样性和寄主植物关联的信息。本研究为了解寄主迁移和害虫起源提供了一个重要的模型系统，可能对开发非化学防治害虫的方法有价值。＊＊＊

9509032 Etges The range of host plants used by groups of insects can be broad or very narrow, including host plant specificity or restriction to a single host. Since most insects, which constitute the vast majority of all animal species, use plants during some part of their life cycles for food or as a place to reproduce, it is important to understand the causes for insects to be host specialists or generalists. Patterns of host use may be important in explaining the diversification of insect groups. Particular aspects of host plants may either limit or increase the number of hosts an insect species can use. Over long time intervals, this may give rise to related groups of insect species that share host affinities. The research project supported by this award will use patterns of DNA sequence data similarities to study the degree of genetic relatedness among a group of over 40 species in the Drosophila mulleri species complex (Insecta: Diptera: Drosophilidae). The pattern of species relationships determined will be compared to the host use of these species in nature. Two clusters of species in this complex, each with three species, will be studied in greater detail for evidence of population level variation in DNA sequence data. The fruit flies in this study group breed on cacti and their larvae feed on cactus host plants. There has been an apparent host shift with some species feeding on the cactus genus Opuntia, whose members are easily recognized by paddle shaped parts, to other cacti whose growth form is columnar or barrel shaped. Knowledge of relationships among the Drosophila species will allow determination of the number of times that this shift between cactus types has occurred. %%% This award will provide information on the biodiversity and host plant associations in a group of specialized cactus feeding flies. This research represents an important model system for understanding host shifts and the origin of insect pests that may be of value in developing non-chemical means of controlling pests. ***