Tetheamyrma

The genus, comprised of two species, appears to be restricted to forests in good condition on Borneo and in the Philippines.

Identification
General and Buenavente (2018), changes in genus definition from Bolton (1991) are numbered

Monomorphic ants. Head and mesosoma densely rugoreticulate dorsally, laterally, and ventrally, except for smooth genal bridge. Head pilosity composed of fine hairs of varying lengths and flexibility.

Antennae with 10 - 11 segments, with very large 2-segmented apical club (1). Antennal scape short, just reaching or barely exceeding posterior margin of compound eye. Antennal scrobe absent. Compound eye small, located laterally, just forward of midlength of head. Frontal carina present or absent (2). Frontal lobe wide, completely concealing torulus, wider than median part of clypeus inserted between them. Posterior median clypeus narrowly inserted between frontal lobes. Anterior clypeus medially with a pair of setae straddling midpoint. Median clypeus narrowly bicarinate. Mandible triangular.

In lateral view, palp formula 2,2 (undissected). Mesosoma in profile with smoothly convex dorsal outline. Metanotal groove impressed or obsolete (3). Propodeum with short, acute, triangular spines. Infradental lamella between propodeal spine and metapleural lobe present or absent (4). Propodeal lobe low and rounded. Propodeal spiracle conspicuous, variable in location. Petiole sculptured. Anteroventral petiolar process present. Anteroventral postpetiolar process present or absent (5). Spongiform tissue on venter of petiole, postpetiole, and first gastral sternite present or absent (6). Spine absent from mesotibia and metatibia. Sting simple and functional.

Distribution
Sabah, Malayasia.

Biology
Spongiform material on the waist segments and base of the gaster ventrally was previously known only in the tribe Dacetini and the non-dacetine genus Dacetinops. Tetheamyrma is not related to either of these and thus represents a third independent evolution of this feature, whose function remains unknown.

Nomenclature

 *  TETHEAMYRMA [Myrmicinae: Stenammini]
 * Tetheamyrma Bolton, 1991: 9. Type-species: Tetheamyrma subspongia, by original designation.