Stereomyrmex anderseni

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  anderseni. Willowsiella anderseni Taylor, 1991a: 285, figs. 6-9 (w.) AUSTRALIA. Combination in Stereomyrmex: Bolton, 2003: 273.

Worker
TL ca. 2.0; HL 0.51; HW (across eyes) 0.46, (maximum behind eyes) 0.47; CI 92; SL 0.29; SI 62; PW 0.35; WL 0.58; midline length of petiolar node 0.14; petiolar node width 0.31; midline length of postpetiole 0.15; postpetiole width 0.33. Smaller than Stereomyrmex dispar, with different proportions. General features as in the accompanying figures.

Head expanded posterolaterally; anterior part of frons somewhat inflated; clypeus inflated anteromedially, median anterior border transverse, shallowly concave, abruptly reflexed ventrally and projecting forwards to slightly overhang the closed mandibles. Mandibles 5-toothed, apical tooth the largest and most acute, the others subequal in size, diminishing slightly from apex. Antennal club indistinctly 3-jointed, the two apical segments enlarged.

Pronotal shoulders narrowly rounded in dorsal view, semi-epaulate. Pronotum on each side with an obtuse ridge extending dorsally from its ventrolateral extremity to the shoulder, so that the anterolateral and lateral sections of the sclerite are more-or-less separated. Dorsum and sides of mesosoma lacking sutures, except for a short ventral section of the promesonotal suture on each side below the spiracle. Propodeal spines short but acute, posterodorsolaterally directed, slightly curved; each subtended by an anterodorsal carina, which defines the lateral margin of the propodeal dorsum; infradental lamellae small, rounded. Propodeal spiracle very small, situated near the middle of the relevant section of the lateral wall of the mesosoma.

Petiole and postpetiole as illustrated; the former much less bulky than in S. dispar, strongly transverse in dorsal view. Postpetiole similarly transverse, shorter at midline than petiole. Petiolar peduncle extremely short, slender; the spiracles minute, each surmounted by a strong angular process, which is clearly visible and approximately right-angular in dorsal view. Base of gaster quite deeply emarginate in dorsal view, closely reflecting posterior outline of postpetiole. Gaster somewhat broad and flattened, especially anteriorly; in side view more-or-less triangular, with apex anteriorly directed. Sting moderately strong, blade-like, without apical appendage.

Pilosity sparse; a few relatively long hairs on clypeus and mandibles, and on apex and underside of gaster; clypeus with a median and 2 lateral setae on anterior margin; shorter hairs sparse on underside of head. Fine pubescence everywhere moderately abundant. Sculpturing vaguely, densely foveolate on head, mesosoma and nodes; less distinct and more shining posteriad; overall somewhat reminiscent of some Crematogaster species. Gaster dorsally vaguely shagreened, dully shining. Colour bright yellow-brown; eyes black; mandibular teeth dark brown; gastral dorsum darkly infuscated, darkest medially.