Data from: Nuclear DNA based species delineations of Coccus scale insects in symbiosis with plants and ants, and the role of plant epicuticular wax in structuring associations

We undertook phylogenetic analysis of nuclear DNA to elucidate species boundaries in the symbiotic Coccus scale insects associated with mutualistic Crematogaster ants and Macaranga plants occurring in the ever-wet forests of Southeast Asia. The coccid specimens clustered into ten lineages, each corresponding to a morphospecies assignment. The lineage identified as C. secretus was separated from the Main Clade by an outgroup. We also examined all pairwise associations among the three symbiont guilds to understand how patterns of association were structured. The analyses revealed that each ant, plant or coccid operational (taxonomic) unit often associated with multiple O(T)Us of each of the other two guilds. However, where testing was feasible, a ‘preference’ for one or sometimes two partner O(T)Us of each guild was often detected. Mutual ‘preferences’ or ‘avoidances’ were relatively common among the symbionts, and no conflicts of interest were apparent. The network of preferred partners among all three guilds showed compartmentalization structured by the presence/absence of plant epicuticular wax, suggesting that this feature plays a fundamental role in how the symbionts select partners that best serve their needs. To a lesser degree, the network was also structured by whether the host plant stems were ant-excavated or hollowed naturally.

本研究通过核DNA系统发育分析，旨在明确与东南亚常绿湿润森林中互利性举腹蚁属（Crematogaster）和血桐属（Macaranga）植物共生的球蚧属（Coccus）介壳虫的物种边界。本次采集的介壳虫标本可划分为10个演化支，每个演化支均对应一个形态种鉴定结果；被鉴定为C. secretus的演化支经外类群分析，与主演化支相互分离。本研究同时对三类共生体功能群间的所有成对关联进行了检测，以解析共生关联模式的构建逻辑。分析结果显示，每一类蚂蚁、植物或介壳虫的操作分类单元（operational taxonomic unit, OTU）往往会与另外两类功能群中各自的多个操作分类单元形成共生关联。不过，在检测条件可行的情况下，研究常能观测到共生体对某一类群中一个（有时为两个）伴侣操作分类单元存在‘偏好性’。共生体之间的相互‘偏好’或‘规避’行为相对常见，且未观测到明显的利益冲突。三类功能群间的偏好伴侣网络呈现出基于植物表皮蜡质有无的分区结构，这表明该特征在共生体筛选最能满足自身需求的伴侣过程中发挥着基础性作用。在较低程度上，该网络的结构还受到寄主植物茎干是否被蚂蚁筑巢挖掘或天然中空的影响。