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.

本研究通过对核DNA开展系统发育分析，旨在明确与互利共生举腹蚁属（Crematogaster）蚂蚁及血桐属（Macaranga）植物伴生的共生蚧属（Coccus）介壳虫的物种边界，研究样本取自东南亚常年湿润森林。介壳虫标本共聚类为10个演化支，每个演化支均对应一个形态种鉴定结果。经外类群检验，被鉴定为C. secretus的演化支与主演化支形成分化。本研究同时对三类共生功能群间的所有成对关联进行了考察，以解析共生关联模式的构建机制。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）通常会与另外两类功能群中的多个OTU形成关联。但在检测条件可行的场景下，研究常能观测到各类群对另一功能群中某一个（有时为两个）关联OTU的“偏好性”。共生生物间的双向“偏好”或“回避”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性关联网络呈现出以植物表皮蜡质有无为依据的分区结构，这表明该特征在共生生物选择最适配自身需求的伴侣过程中发挥着基础性作用。在较小程度上，该网络的结构还受宿主植物茎干是否经蚂蚁筑巢挖掘或天然中空的影响。