Phylogeny and revised classification of the saucer bugs (Hemiptera: Nepomorpha: Naucoridae)

The true bug infraorder Nepomorpha contains 11 families with classifications mostly using morphological features and not based on phylogenetic analyses. Presented here is the first molecular-based phylogeny for a family of Nepomorpha including more than half of the constituent taxa. Two nuclear (18S rRNA and 28S rRNA) and two mitochondrial (COI and COII) genes were used to reconstruct phylogenetic relationships with both Bayesian inference and maximum likelihood analyses. Ingroup taxa included all six subfamilies, 41 of the 43 genera, and 221 species and subspecies. Results of the analyses were mostly congruent and revealed Naucoridae to be monophyletic, but two of the subfamilies (Cheirochelinae and Naucorinae) and three genera (Heleocoris, Laccocoris and Naucoris) as polyphyletic. Two clades formerly in Naucorinae were recovered as distinct subfamily-level clades: Macrocorinae subfam. nov. contains the African Macrocoris and Neomacrocoris, and Ilyocorinae stat. nov. contains the Palaearctic Ilyocoris and Neotropical Placomerus. Laccocorinae is unchanged in its constituent membership, but its organization now includes four tribe-level groups. Limnocorinae and the recently revised Cryphocricinae and Ambrysinae are unchanged. An annotated list of all subfamily-, tribe- and genus-group taxa is presented, including new taxa descriptions, synonymies and new combinations.

Automated summary

This study presents the first molecular-based phylogeny for a family of the true bug infraorder Nepomorpha, providing insights into the relationships among its constituent taxa. The results reveal Naucoridae to be a monophyletic group, but identify Cheirochelinae, Naucorinae, and certain genera as polyphyletic. Additionally, two distinct subfamily-level clades were recovered from Naucorinae, and the organization of Laccocorinae was revised to include four tribe-level groups.