Omoplax Horváth, 1912

Souma, Jun, 2022, Two new species of the genus Omoplax (Hemiptera: Heteroptera: Tingidae) from Mukojima Island, with new records of lace bugs endemic to the Ogasawara Islands, Japan, Acta Entomologica Musei Nationalis Pragae 62 (1), pp. 117-127 : 118

Omoplax Horváth, 1912

Omoplax Horváth, 1912: 336 (as subgenus of Stephanitis ; upgraded by

TൺKൾඒൺ 1962: 74). Type species by monotypy: Stephanitis (Omoplax)

desecta Horváth, 1912.

For detailed description see HඈඋඏගඍH (1912) and Sඈඎආൺ

& Kൺආංඍൺඇං (2021).

Remarks. According to Sඈඎආൺ & Kൺආංඍൺඇං (2021), Omoplax can be distinguished from the allied Acanthomoplax by the following characteristics: head with very short spines (with long spines in Acanthomoplax ); paranotum carinate in anterior part and rounded in posterior part (rounded throughout its length in Acanthomoplax ); outer margin of paranotum not sinusoidal in dorsal view (sinusoidal in dorsal view in Acanthomoplax ), without robust denticles throughout its length (with robust denticles throughout its length in Acanthomoplax ); anterior margin of hemelytron without robust denticles throughout its length (with robust denticles throughout its length in Acanthomoplax ); R+M (radiomedial) vein of hemelytron indistinct (distinct in Acanthomoplax ), without denticles throughout its length (with denticles throughout its length in Acanthomoplax ). However, O. karubei sp. nov. and O. mukojimensis sp. nov., which are described below, closely match the diagnostic characteristics of Omoplax (cf. HඈඋඏගඍH 1912; Sඈඎආൺ & Kൺආංඍൺඇං 2021) but possess a rounded anterior part of the paranotum. Like in Acanthomoplax , O. majorcarinae occasionally possesses the rounded anterior part of the paranotum, and O. karubei sp. nov. possesses a distinct hemelytral R+M vein. Therefore, these two new species seem to be best placed in Omoplax ; however, Omoplax cannot be distinguished from Acanthomoplax in the carinate anterior part of the paranotum and the indistinct hemelytral R+M vein. In addition to the diagnostic characters provided by Sඈඎආൺ & Kൺආංඍൺඇං (2021) except for the aforementioned two features, Omoplax is separated from Acanthomoplax by the posteriorly widened paranotum (posteriorly narrowed in Acanthomoplax ). In conclusion, Omoplax is still distinguished from Acanthomoplax by the following characteristics: head with very short spines; paranotum widened posteriad; outer margin of paranotum without robust denticles throughout its length; and anterior margin of hemelytron without robust denticles throughout their length; and R+M vein of hemelytron without denticles throughout its length.