Department of Entomology, South China Agricultural University, Guangzhou, People's Republic of China.
PLoS One. 2013;8(1):e53084. doi: 10.1371/journal.pone.0053084. Epub 2013 Jan 7.
Bemisia tabaci (Hemiptera: Aleyrodidae) is a globally distributed pest composed of at least 34 morphologically indistinguishable cryptic species. At least seven species of endosymbiont have been found infecting some or all members of the complex. The origin(s) of the associations between specific endosymbionts and their whitefly hosts is unknown. Infection is normally vertical, but horizontal transmission does occur and is one way for new infections to be introduced into individuals. The relationships between the different members of the cryptic species complex and the endosymbionts have not been well explored. In this study, the phylogenies of different cryptic species of the host with those of their endosymbionts were compared. Of particular interest was whether there was evidence for both coevolution and horizontal transmission. Congruence was observed for the primary endosymbiont, Portiera aleyrodidarum, and partial incongruence in the case of two secondary endosymbionts, Arsenophonus and Cardinium and incongruence for a third, Wolbachia. The patterns observed for the primary endosymbiont supported cospeciation with the host while the patterns for the secondary endosymbionts, and especially Wolbachia showed evidence of host shifts and extinctions through horizontal transmission rather than cospeciation. Of particular note is the observation of several very recent host shift events in China between exotic invader and indigenous members of the complex. These shifts were from indigenous members of the complex to the invader as well as from the invader to indigenous relatives.
烟粉虱（半翅目：粉虱科）是一种分布广泛的害虫，由至少 34 种形态上无法区分的隐种组成。至少有七种内共生菌已被发现感染该复合种群的某些或全部成员。特定内共生菌与其粉虱宿主之间的联系起源尚不清楚。感染通常是垂直的，但也会发生水平传播，这是新感染引入个体的一种方式。不同隐种复合体成员与内共生菌之间的关系尚未得到很好的探索。在这项研究中，比较了宿主不同隐种的系统发育与它们的内共生菌的系统发育。特别感兴趣的是是否有共同进化和水平传播的证据。主要内共生菌 Portiera aleyrodidarum 存在一致性，而两种次要内共生菌 Arsenophonus 和 Cardinium 则存在部分不一致性，第三种内共生菌 Wolbachia 则存在不一致性。主要内共生体观察到的模式支持与宿主的共进化，而次要内共生体，特别是 Wolbachia 的模式则显示出通过水平传播而不是共进化发生宿主转移和灭绝的证据。值得注意的是，在中国观察到了几种非常近期的外来入侵种与该复合种群中本地成员之间的宿主转移事件。这些转移既发生在本地成员到入侵种之间，也发生在入侵种到本地亲属之间。
