SUBFAMILY NAUCORINAE LEACH, 1815

FIGS 10H, 11H, 17, 19, 22–25

Type species: Naucoris maculatus Fabricius, 1798 .

Taxonomic history: The nominate subfamily was recognized as the division Naucoraria by Stål (1876) to include Ilyocoris, Macrocoris, Naucoris and Pelocoris . The group was referenced as subfamily Naucorinae by Montandon (1900) when describing Macrocoris parviceps . Since then, additional genera have been described and placed in Naucorinae, but the subfamily was not based on any synapomorphies and the monotypy has been considered doubtful (e.g. Sites & Mbogho, 2012). The genus Carvalhoiella was described in Ambrysinae (De Carlo, 1963), then was transferred to Naucorini (Nieser, 1975), but was later transferred back to Ambrysinae (Nieser et al., 1999) . Zettel (2001) suggested the tribe Ilyocorini to contain Ilyocoris, Pelocoris and Placomerus and Naucorini to contain Asthenocoris, Macrocoris, Nanonaucoris, Naucoris, Neomacrocoris, Philippinocoris, Stalocoris and Thurselinus Distant, 1904 . In the description of Halmaheria, Zettel (2007) noted a series of attributes suggesting a close relationship of this new genus with both Sagocorini ( Cheirochelinae) and Naucorini (Naucorinae) . Therefore, he transferred the Philippine genera of Sagocorini ( Asthenocoris, Philippinocoris and Stalocoris) to Naucorini . Recently, Pelocoris was transferred from Naucorinae to Ambrysinae (ReynosoVelasco & Sites, 2021) .

Revised taxonomy: In my Most Probable Phylogeny dendrogram (Fig. 9), I substituted the ML topology of Clade O, the predominantly New Guinean clade, into the BI dendrogram to represent what I consider to be the most plausible, supported evolutionary relationships within the subfamily. The revised subfamily Naucorinae presented in the Most Probable Phylogeny has four major clades (Fig. 18), each of which represents a tribe and includes a species of Naucoris (Fig. 19) at its root with strong support. Because the genus Naucoris, as currently conceived, is clearly polyphyletic, new genera will be necessary for species of Naucoris in all but one clade. Because these species were previously considered congeners, morphological distinctions supporting their recognition as multiple genera are not evident in some cases. Nonetheless, the molecular evidence presented here that Naucoris as currently conceived is polyphyletic is strong.

Diagnosis: With the recent transfer of Pelocoris to Ambrysinae, Ilyocoris and Placomerus to Ilyocorinae, and Macrocoris and Neomacrocoris to Macrocorinae, a clear synapomorphy among genera in Naucorinae is now evident. The male parameres are large, crisscrossing and dramatically asymmetrical in all species. More specifically, the left paramere overlaps the right and is broader and slightly shorter than the right. The right paramere tends to have a sulcus or elongated fossa on its right side to accommodate the left side of the aedeagus shaft. Both parameres wrap around and embrace the aedeagus (Fig. 11h).

Comments: Because each of these tribe groups has one or more species of Naucoris at the root, this suggests that an especially vagile ancestral Naucoris -like taxon dispersed widely, giving rise to multiple independent lineages of naucorids. This concept was astutely hypothesized by Polhemus & Polhemus (1987) when considering the origins of the Philippine and New Guinean stock based on head structure and male genitalia. We now have strong corroborating molecular evidence for these relationships.