A phylogeny of Naucoridae (Heteroptera) using whole mitochondrial genomes

Naucoridae (Hemiptera: Heteroptera: Nepomorpha), commonly known as creeping water bugs, is an aquatic insect family with 369 described species worldwide, with greatest species richness concentrated in tropical regions. All naucorids are predaceous and are important constituents of the aquatic macroinvertebrate communities they inhabit, acting as keystone consumers. They can be found in a wide range of habitats, including brackish water, algal mats, streambeds, riffles, waterfall splash zones, and vertical rock faces, and frequently exhibit high levels of localization. The phylogenetic relationships of Naucoridae, both in respect to other members of the infraorder Nepomorpha and within the family itself, have been subject to much debate and revision. Currently, five subfamilies are recognized based on morphology; however, the validity of these groups remains untested by phylogenetic methods, and their monophyly is uncertain. Additionally, there has been no phylogenetic treatment of lower level taxa. To resolve this uncertainty, whole mitochondrial genomes from several species of Naucoridae, distributed across all major intrafamilial taxa, were sequenced and used to evaluate phylogenetic relationships. Sequencing was carried out on the Illumina Genome Analyzer II, a 'next-generation' sequencing platform. This research is one of the first instances of this newly emerging technology being utilized in insect phylogenomics. Select branches of the resulting phylogenetic trees depict likely evolutionary relationships among currently recognized genera, tribes, and subfamilies. Data support the monophyly of several constituent taxa, including several island-endemic groups (e.g., Sagocorini), although further analysis is needed, and recognition of Cheirochelinae as it is currently organized is questionable.