Dissertation Research: Natural Selection and the Role of Pheromones in Colias

密切相关的硫蝶，Colias eurytheme和C. philodice，共存于北美的大部分地区。虽然它们能够杂交，但每个物种的雌性通常通过评估求爱雄性提供的视觉和化学（即信息素）信息来阻止这种杂交。泰勒和他的同事们现在有证据表明，一个物种内的雄性信息素在数量和质量上都是变化很大的，而且未交配的雌性经常拒绝一些追求自己物种的雄性，而接受其他雄性。关于紫茎草的初步数据普遍支持这样一种假设，即根据构成其信息素的化学物质的质量或数量，一只原本合适的求偶雄性可能会被雌性拒绝或接受。尽管在鉴定许多昆虫物种的信息素方面已经做了大量的工作，但对物种内信息素变异的程度或种类知之甚少，而且实际上对导致这种变异的原因及其对交配行为的影响一无所知。特别适合作为研究昆虫信息素在种内变异作用的模式种。求偶系统在行为和遗传上都得到了很好的理解，信息素成分已经被确定，这些物种可以在实验室中大量饲养，使它们容易受到基因操作和行为实验的影响。现代虫害管理方法通常包括使用虫害物种的信息素进行抽样或实际尝试进行抑制。这项研究的结果应该清楚地表明，信息素的变化可能是相当大的，不能总是被忽视。

The closely related sulfur butterflies, Colias eurytheme and C. philodice, coexist over much of North America. Although they are capable of hybridizing, the females of each species normally prevent this by evaluating both visual and chemical (i.e., pheromonal) information provided by courting males. Taylor and colleagues now have evidence that the male pheromones within a species are quite variable both in quantity and quality and that unmated females often reject some courting males of their own species while accepting others. Preliminary data on C. eurytheme generally support the hypothesis that an otherwise suitable courting male may be rejected or accepted by a female based on the qualities or quantities of the chemicals making up its pheromone. Although a vast amount of work has been done on the identification of pheromones of many insect species, relatively little is known about the extent or kind of within-species pheromone variation, and practically nothing is known about what causes this variation or its effects on mating behavior. Colias eurytheme and C. philodice are exceptionally suited to serve as model species for examining the role of within-species variation in insect pheromones. The courtship system is well understood both behaviorally and genetically, the pheromone components have been identified, and these species can be mass-reared in the laboratory making them susceptible to genetic manipulation and behavioral experimentation. Modern methods of pest-management often include the use of the pest-species' pheromone either for sampling or for actual attempts at suppression. The result of this study should make clear that pheromone variation can be considerable and cannot always be ignored.