Phytophagous insects are among the most diverse of the earth’s organisms, and their diversification patterns and the driving forces behind these have attracted considerable research interest. Host shifting to closely related plant species is thought to play an important role in phytophagous insect diversification, but the extent to which other interactions such as mutualistic associations affect diversification is not yet known. In this study, we reconstructed the molecular phylogeny of Japanese Stomaphis aphids and determined whether host shifting or mutualistic association with different ant species could explain diversification in this aphid genus. We analyzed 12 species of Stomaphis and grouped them into ten well-supported DNA lineages. Species in each lineage used a single or a few host plant species, but were mutualistically associated with many ant species of the genus Lasius. This result suggests that Stomaphis evolutionarily diversified primarily through host plant shifts. Interestingly, the reconstructed phylogeny suggests that Stomaphis host shifts occasionally occurred between very distantly related host plant taxa (spanning up to five plant orders). The dependence of Stomaphis on long-lasting Lasius ant colonies situated in temperate deciduous forests where Lasius is the dominant ant genus may have led the aphids to shift to distantly related but spatially adjacent host tree species.

中文翻译：

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日本气孔蚜的进化多样性（与蚜虫的寄主植物使用和蚂蚁相关）。

噬食性昆虫是地球上最多样化的生物之一，其多样化模式及其背后的驱动力引起了相当大的研究兴趣。寄主转移到密切相关的植物物种被认为在植物吞噬性昆虫的多样化中起着重要作用，但是尚不知道其他相互作用（例如相互关系）在多大程度上影响多样化。在这项研究中，我们重建了日本气孔蚜的分子系统发育，并确定宿主的转移或与不同蚂蚁物种的相互关联是否可以解释该蚜虫属的多样性。我们分析了12种气孔并将它们分为十个得到良好支持的DNA谱系。每个谱系中的物种仅使用一种或几种寄主植物物种，但与Lasius属的许多蚂蚁物种相互关联。该结果表明，气孔菌主要通过宿主植物的转移而进化上多样化。有趣的是，重建的系统发育表明，气孔寄主的转移有时发生在距离很远的寄主植物类群之间（跨越多达五个植物顺序）。的依赖Stomaphis的长效Lasius蚁群位于温带落叶林，其中Lasius 是主要的蚂蚁属可能导致蚜虫转移到远缘相关但在空间上相邻的寄主树种。