Myrmica Latreille, 1804

Taxonomy. The genus Myrmica is assigned to the tribe Myrmicini (Bolton 2003). The Vietnamese species were recently revised by Radchenko & Elmes (2001) and Radchenko et al. (2006), and the workers have the following features.

Worker monomorphic; head in full-face view oval; preoccipital carina distinct dorsally and laterally; frontal carina and antennal scrobe absent; anteromedian margin of clypeus weakly convex, lacking an isolated median seta; posteromedian portion of clypeus broadly inserted between frontal lobes; antennae 12-segmented, without distinct club; eye medium sized, convex well laterad; palp formula 6,4; mandible triangular; masticatory margin with apical and 1-2 distinct preapical teeth followed by several smaller teeth or denticles; promesonotum in lateral view slightly raised; promesonotal suture absent or vestigial dorsally; metanotal groove more or less distinctly impressed dorsally; propodeal spine long and sharp; propodeal lobe well developed as a triangular or spinose projection; middle and hind tibiae usually each with a single pectinate spur; petiole pedunculate, with low node; subpetiolar process present as a small tooth anteroventrally; dorsal part of postpetiole in lateral view leaning posterodorsad; gastral shoulder absent; sting well developed, without any apical appendage; head and mesosoma usually strongly reticulate or rugoso-reticulate.

The worker of Myrmica is somewhat similar to those of Aphaenogaster (see under Aphaenogaster) and Tetramorium. However, in the worker of Tetramorium, the tibial spurs of the middle and hind legs are simple or absent, and the apex of sting bears a small lamellate appendage.

Vietnamese species. Five species have been known from Vietnam: angulata Radchenko & Elmes (Sa Pa); schoedli Radchenko, Elmes & Bui (Sa Pa); serica Wheeler (Sa Pa); titanica Radchenko & Elmes (Sa Pa); yamanei Radchenko & Elmes (Sa Pa).

Bionomics. Myrmica species have so far been found exclusively in the mountains of Fan Si Pan above approximately1,700 m alt. They inhabit sparse to well-developed forests and nest in rotting logs, wood fragments, under stones, in soil around tree bases, etc. Workers forage on the ground and lower vegetation.