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 ...

本研究通过核DNA系统发育分析，旨在明确东南亚常绿湿润林中与互利性举腹蚁（Crematogaster）及血桐属（Macaranga）植物共生的球蚧属（Coccus）介壳虫的物种边界。所获介壳虫标本共聚类为10个支系，每个支系均对应一个形态种鉴定结果。经鉴定为C. secretus的支系，通过外类群分析与主支系相互分离。本研究同时对三类共生生物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，每一个蚁类、植物或介壳虫的操作分类单元（operational taxonomic unit，OTU）通常会与另外两类共生功能群中的多个对应操作分类单元形成关联。不过，在检测条件可行的情况下，研究常能观测到各类群对另一类群中某一个（有时为两个）关联操作分类单元的‘偏好性’。共生功能群间的双向‘偏好’或‘规避’行为相对常见，且未发现明显的利益冲突。偏好性关联伙伴所构成的网络……