Percy Diana M
Department of Life Sciences, Natural History Museum, Cromwell Road, London, UK, and University of British Columbia, Faculty of Science, University Boulevard, Vancouver, BC, Canada.
Zookeys. 2017 Jan 31(649):1-163. doi: 10.3897/zookeys.649.10213. eCollection 2017.
The Hawaiian psyllids (Psylloidea, Triozidae) feeding on Metrosideros (Myrtaceae) constitute a remarkable radiation of more than 35 species. This monophyletic group has diversified on a single, highly polymorphic host plant species, Metrosideros polymorpha. Eleven Metrosideros-feeding species included in the Insects of Hawaii by Zimmerman are redescribed, and an additional 25 new species are described. Contrary to previous classifications that placed the Metrosideros-feeders in two genera, Trioza Foerster, 1848 and Kuwayama Crawford, 1911, all 36 named species are placed in Pariaconus Enderlein, 1926; and the relationship of this genus to other Pacific taxa within the family Triozidae, and other Austro-Pacific taxa feeding on host plants in Myrtaceae is clarified. The processes of diversification in Pariaconus include shifts in galling habit, geographic isolation within and between islands, and preferences for different morphotypes of the host plant. Four species groups are recognized: the bicoloratus and minutus groups are free-living or form pit galls, and together with the kamua group (composing all of the Kauai species) form a basal assemblage; the more derived closed gall species in the ohialoha group are found on all major islands except Kauai. The diversification of Pariaconus has likely occurred over several million years. Within island diversification is exemplified in the kamua group, and within species variation in the ohialoha group, but species discovery rates suggest this radiation remains undersampled. Mitochondrial DNA barcodes are provided for 28 of the 36 species. Genetic divergence, intraspecific genetic structure, and parallel evolution of different galling biologies and morphological traits are discussed within a phylogenetic framework. Outgroup analysis for the genus Pariaconus and ancestral character state reconstruction suggest pit-galling may be the ancestral state, and the closest outgroups are Palaearctic-Australasian taxa rather than other Pacific Metrosideros-feeders.
以桃金娘科的铁树属植物为食的夏威夷木虱（木虱总科，澳木虱科）构成了一个由35多个物种组成的显著辐射类群。这个单系类群在单一的、高度多态的寄主植物物种——多形铁树上实现了多样化。对齐默尔曼所著《夏威夷昆虫》中收录的11种以铁树属植物为食的物种进行了重新描述，并描述了另外25个新物种。与之前将以铁树属植物为食的木虱分为两个属（1848年的澳木虱属和1911年的桑山木虱属）的分类不同，所有36个已命名的物种都被归入1926年的帕里亚锥属；并阐明了该属与澳木虱科内其他太平洋类群以及以桃金娘科寄主植物为食的其他澳大拉西亚-太平洋类群之间的关系。帕里亚锥属的多样化过程包括虫瘿习性的转变、岛屿内部和岛屿之间的地理隔离以及对寄主植物不同形态型的偏好。确认了四个物种组：双色组和微小组为自由生活或形成坑状虫瘿，它们与卡穆阿组（包括考艾岛的所有物种）一起构成一个基部类群；在除考艾岛之外的所有主要岛屿上都发现了奥希亚洛哈组中更为衍生的封闭虫瘿物种。帕里亚锥属的多样化可能发生在几百万年的时间里。岛屿内部的多样化以卡穆阿组为例，物种内部的变异以奥希亚洛哈组为例，但物种发现率表明这个辐射类群的采样仍然不足。为36个物种中的28个提供了线粒体DNA条形码。在系统发育框架内讨论了遗传分歧、种内遗传结构以及不同虫瘿生物学和形态特征的平行进化。对帕里亚锥属的外类群分析和祖先特征状态重建表明，形成坑状虫瘿可能是祖先状态，最接近的外类群是古北界-澳大拉西亚类群，而不是其他以铁树属植物为食的太平洋类群。
