Opamyrma Yamane, Bui et Eguchi, 2008

Eguchi, Katsuyuki, Viet, Bui Tuan & Yamane, Seiki, 2014, Generic Synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), Part II — Cerapachyinae, Aenictinae, Dorylinae, Leptanillinae, Amblyoponinae, Ponerinae, Ectatomminae and Proceratiinae, Zootaxa 3860 (1), pp. 1-46 : 24-25

Opamyrma Yamane, Bui et Eguchi, 2008

Taxonomy. The genus Opamyrma was established for a single species, O. hungvuong , and is morphologically very close to Apomyrma known from the Afrotropical region ( Yamane et al. 2008).

Morphology. Worker presumably monomorphic; body long and slender, with long legs; head in full-face view subrectangular, and somewhat flattened dorsoventrally; preoccipital carina complete, almost encircling the head slightly before its posterior margin; frontal lobe, frontal carina and antennal scrobe absent; median part of clypeus rather clearly divided into posterior horizontal portion and anterior steep slope; the posterior portion distinctly separated from frons with a continuous carina, and broadly inserted between antennal sockets; lateral part of clypeus narrow from front to back; mandible slender, with long but bluntly tapered apical tooth followed by a trapezoidal lobe and three inconspicuous teeth; labrum on its outer face with at least two rows of peg-like denticles; eye absent; antennal sockets completely exposed in full-face view, located in a large, roundly excavated area whose anterior wall is steep just behind posterior margin of clypeus; antenna 12-segmented, gradually incrassate from segment II to XII; mesosoma slender, in lateral view flattened dorsally; promesonotal suture present and flexible; metanotal groove absent dorsally; propodeum unarmed; orifice of propodeal spiracle round, situated relatively low on lateral face of propodeum; propodeal lobe much reduced; mid- and hind tibiae each with a reduced barbulate anterior spur in front of a well-developed pectinate posterior spur; waist consisting of a single segment (petiole); petiole extremely elongate, virtually without anterior peduncle, narrowly attached to abdominal segment III; tergosternal sutures of petiole present; petiolar spiracle located anteriorly on lateral face of petiole at its mid-height; gaster (consisting of abdominal segments III–VII) extremely elongate; abdominal segment III above helcium with free anterior face; spiracles on segments V–VII concealed by the preceding segments; segment VII longest among the segments III–VII; pygidium and hypopygium unarmed laterally and posteriorly.

Differentiation. The worker of Opamyrma is easily distinguished from that of the other Vietnamese genera of Amblyoponinae by a combination of the following features: petiole narrowly attached to abdominal segment III (gastral segment I); abdominal segment III above helcium with free anterior face; frontal lobe completely absent, thus antennal socket in full-face view fully exposed.

Vietnamese species (1 sp.).

O. hungvuong Yamane, Bui et Eguchi, 2008 . Type locality: Huong Son Forest (so far been known only from the type series).

Bionomics. Unknown.