Escalona Hermes E, Zwick Andreas, Li Hao-Sen, Li Jiahui, Wang Xingmin, Pang Hong, Hartley Diana, Jermiin Lars S, Nedvěd Oldřich, Misof Bernhard, Niehuis Oliver, Ślipiński Adam, Tomaszewska Wioletta
Centre for Molecular Biodiversity Research (ZMB), Museum Alexander Koenig, Adenauerallee, 53113, Bonn, Germany.
Australian National Insect Collection, CSIRO, GPO Box 1700, Canberra, ACT 2601, Australia.
BMC Evol Biol. 2017 Jun 26;17(1):151. doi: 10.1186/s12862-017-1002-3.
The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity. Many species are aphidophagous, feeding as larvae and adults on aphids, but some species also feed on other hemipterous insects (i.e., heteropterans, psyllids, whiteflies), beetle and moth larvae, pollen, fungal spores, and even plant tissue. Several species are biological control agents or widespread invasive species (e.g., Harmonia axyridis (Pallas)). Despite the ecological importance of this tribe, relatively little is known about the phylogenetic relationships within it. The generic concepts within the tribe Coccinellini are unstable and do not reflect a natural classification, being largely based on regional revisions. This impedes the phylogenetic study of important traits of Coccinellidae at a global scale (e.g. the evolution of food preferences and biogeography).
We present the most comprehensive phylogenetic analysis of Coccinellini to date, based on three nuclear and one mitochondrial gene sequences of 38 taxa, which represent all major Coccinellini lineages. The phylogenetic reconstruction supports the monophyly of Coccinellini and its sister group relationship to Chilocorini. Within Coccinellini, three major clades were recovered that do not correspond to any previously recognised divisions, questioning the traditional differentiation between Halyziini, Discotomini, Tytthaspidini, and Singhikaliini. Ancestral state reconstructions of food preferences and morphological characters support the idea of aphidophagy being the ancestral state in Coccinellini. This indicates a transition from putative obligate scale feeders, as seen in the closely related Chilocorini, to more agile general predators.
Our results suggest that the classification of Coccinellini has been misled by convergence in morphological traits. The evolutionary history of Coccinellini has been very dynamic in respect to changes in host preferences, involving multiple independent host switches from different insect orders to fungal spores and plants tissues. General predation on ephemeral aphids might have created an opportunity to easily adapt to mixed or specialised diets (e.g. obligate mycophagy, herbivory, predation on various hemipteroids or larvae of leaf beetles (Chrysomelidae)). The generally long-lived adults of Coccinellini can consume pollen and floral nectars, thereby surviving periods of low prey frequency. This capacity might have played a central role in the diversification history of Coccinellini.
瓢虫族是一类体型相对较大的瓢虫，展现出显著的形态和生物多样性。许多物种以蚜虫为食，幼虫和成虫均以蚜虫为食，但有些物种也取食其他半翅目昆虫（即异翅亚目昆虫、木虱、粉虱）、甲虫和蛾类幼虫、花粉、真菌孢子，甚至植物组织。有几个物种是生物防治剂或广泛分布的入侵物种（如异色瓢虫（Harmonia axyridis (Pallas)））。尽管该族具有重要的生态学意义，但对其内部的系统发育关系却知之甚少。瓢虫族内的属概念不稳定，不能反映自然分类，很大程度上是基于区域修订。这阻碍了在全球范围内对瓢虫科重要性状的系统发育研究（如食性偏好和生物地理学的进化）。
我们基于38个分类单元的三个核基因和一个线粒体基因序列，对瓢虫族进行了迄今为止最全面的系统发育分析，这些分类单元代表了瓢虫族所有主要谱系。系统发育重建支持瓢虫族的单系性及其与红瓢虫族的姐妹群关系。在瓢虫族内，识别出三个主要分支，它们与之前认可的任何分类都不对应，这对传统上对盔唇瓢虫亚族、盘瓢虫亚族、小毛瓢虫亚族和方瓢虫亚族的区分提出了质疑。食性偏好和形态特征的祖先状态重建支持蚜虫捕食是瓢虫族祖先状态的观点。这表明从与其亲缘关系密切的红瓢虫族中所见的假定专性介壳虫取食者，向更灵活的一般捕食者的转变。
我们的结果表明，瓢虫族的分类受到形态特征趋同的误导。瓢虫族的进化历史在寄主偏好变化方面非常动态，涉及从不同昆虫目到真菌孢子和植物组织的多次独立寄主转换。对短暂存在的蚜虫的一般捕食可能创造了一个机会，使其能够轻松适应混合或特殊的食物（如专性食菌、食草、捕食各种半翅目昆虫或叶甲科（叶甲虫）幼虫）。瓢虫族成虫通常寿命较长，可以消耗花粉和花蜜，从而在猎物频率较低的时期存活下来。这种能力可能在瓢虫族的多样化历史中发挥了核心作用。
