Havill Nathan P, Foottit Robert G, von Dohlen Carol D
Department of Ecology and Evolutionary Biology, 165 Prospect St., Yale University, New Haven, CT 06520, USA.
Mol Phylogenet Evol. 2007 Jul;44(1):357-70. doi: 10.1016/j.ympev.2006.11.008. Epub 2006 Nov 17.
The Adelgidae form a small group of insects in the Aphidoidea. They are cyclically parthenogenetic with host alternating, multiple-generation complex life cycles and are restricted to certain host genera in the Pinaceae. Species that host alternate always have Picea as the primary host where sexual reproduction and gall formation occur, and another genus in the Pinaceae as the secondary host where a series of parthenogenetic generations are produced. Other species that do not host alternate complete their entire life cycle on one host and only reproduce parthenogenetically. We studied relationships within Adelgidae using DNA sequences from the mitochondrial COI, COII, and cytb genes, and the nuclear EF1alpha gene. Analysis of the combined data resulted in a well-resolved phylogeny in which the major adelgid clades correspond neatly to their association with secondary host genera. Specialization on each secondary host genus occurred only once and was followed by diversification on the host genus. Molecular dating of divergence times in the Adelgidae suggest that diversification among host genera occurred in the Late Cretaceous and Early Tertiary when the Pinaceae genera were diverging. It is not clear, however, whether the Adelgidae and Pinaceae co-diversified because the relationships among the Pinaceae genera are not fully resolved. We discuss implications for adelgid taxonomy, life cycle evolution, and evolution of the interaction between adelgids and their host plants.
球蚜科是蚜总科中的一小类昆虫。它们进行周期性孤雌生殖，具有寄主交替、多代复杂的生命周期，并且局限于松科的某些寄主属。进行寄主交替的物种总是以云杉作为主要寄主，在其上进行有性生殖和虫瘿形成，而以松科中的另一个属作为次要寄主，在其上产生一系列孤雌生殖代。其他不进行寄主交替的物种在一个寄主上完成其整个生命周期，并且只进行孤雌生殖。我们使用线粒体COI、COII和cytb基因以及核EF1alpha基因的DNA序列研究了球蚜科内部的关系。对合并数据的分析产生了一个解析良好的系统发育树，其中主要的球蚜类群与其与次要寄主属的关联整齐对应。对每个次要寄主属的特化只发生过一次，随后在寄主属上发生了多样化。球蚜科分歧时间的分子定年表明，寄主属之间的多样化发生在白垩纪晚期和第三纪早期，当时松科各属正在分化。然而，尚不清楚球蚜科和松科是否共同分化，因为松科各属之间的关系尚未完全解析。我们讨论了对球蚜分类学、生命周期进化以及球蚜与其寄主植物之间相互作用进化的影响。
