Collaborative Research: Host-Associated Genetic Differentiation in the Goldenrod Elliptical-Gall Moth Gnorimoschema Gallaesolidaginis - Parallel Host Race Formation?

[10775 . 52]草食性昆虫惊人的多样性（1-5百万种）尚不清楚，但它们多样化的一种可能机制是通过寄主种族形成的同域物种形成，即在没有基因交换地理障碍的情况下，对不同寄主植物的适应和物种形成。虽然已知同系体中少数宿主种族形成的情况，但尚不清楚这一过程是罕见和特殊的，还是频繁和可预测的。为回答这个问题提供了一个有希望的途径，那就是攻击黄花（Solidago altissima）和黄花（S. gigantea）的不同昆虫群体。本文将以黄花椭圆瘿蛾（Gnorimoschema gallaesolidaginis）为研究对象，利用遗传数据记录遗传分化的地理范围和结构，重建寄主迁移的历史，并确定驱动分化的进化力量。同时，我们将利用实验室和野外实验来确定维持寄主植物亲和性和生殖隔离的生态机制（例如配偶选择、成虫和幼虫寄主的选择和/或幼虫性能中与寄主相关的权衡）。我们的研究将补充正在进行的其他黄牛花食草动物分化的研究。总之，这些研究将告诉我们寄主种族的形成是如何（以及多久）促成了食草昆虫的惊人多样化。

0107752HeardThe astounding diversity of herbivorous insects (1-5 million species) is poorly understood, but one possible mechanism for their diversification is sympatric speciation via host race formation - that is, adaptation to and speciation on different host plants in the absence of geographic barriers to gene exchange. While a few cases of host race formation in sympatry are known, it remains un-known whether this process is rare and special or frequent and predictable. A promising avenue toward answering this question is provided by the diverse group of insects attacking the goldenrods Solidago altissima and S. gigantea. Focussing on one of these insects, the goldenrod elliptical-gall moth, Gnorimoschema gallaesolidaginis, we will use genetic data to document the geographic extent and structure of genetic differentiation, reconstruct the history of host shifting, and identify evolutionary forces driving differentiation. At the same time, we will use lab and field experiments to identify ecological mechanisms maintaining host plant affiliation and reproductive isolation (e.g. mate choice, adult and larval host choice, and/or host-associated tradeoffs in larval performance). Our studies of differentiation in G. gallaesolidaginis will complement ongoing studies of differentiation in other Solidago herbivores. Together, these studies will tell us much about how (and how often) host race formation might have contributed to the spectacular diversification of herbivorous insects.