Strumigenys acubecca group

Strumigenys acubecca group Bolton (2000)

Worker Diagnosis
Mandibles in full-face view and at full closure elongate and narrow, sublinear, flattened from side to side and shallowly convex along their length, only engaging at their extreme apices. A large space present between the mandibles, through which the labral lobes are visible. In profile dorsal surface of mandible slopes upward from base to about midlength, where it rises to a broad triangular peak, then slopes downward to the apex. In ventral view outer margin of mandible without a prebasal inflected angle. MI 27-30.

Dentition. Apex of mandible with a short vertically arranged array of minute denticles that terminates dorsally in a small tooth. Margin between this tooth and the tridentate basal lamella with a single small tooth present. Margins proximal of the basal lamella edentate and widely separated.

Basal lamella at about the midlength of the exposed mandible, the lamella directed almost vertically and its dorsal surface modified into a cluster of 3 teeth, the median of which is by far the largest, subspiniform and almost touching its counterpart from the opposite mandible at full closure.

Labrum terminates in a pair of narrow subconical lobes.

Clypeus with anterior margin shallowly convex, the midpoint with a small anteriorly directed spine. Lateral margins of clypeus parallel or extremely feebly divergent posteriorly. Fully closed mandibles intersecting the anterior margin at its anterolateral angles.

Clypeal dorsum and sides with fine short hairs that are slightly flattened and curved or inclined anteriorly.

Preocular carina conspicuous in full-face view.

Ventrolateral margin of head bluntly rounded in front of the minute eye; weakly marginate closer to the mandibular insertions. Postbuccal impression very small in profile but hypostomal shield of buccal cavity deeply projecting ventrally.

Cuticle of side of head within scrobe reticulate-punctate.

Scape very long, SI 113-120, narrow and cylindrical.

Leading edge of scape with apically directed minute pubescence.

Pronotum sharply marginate dorsolaterally, the dorsum depressed between the marginations and without a median carina.

Propodeum armed with a pair of thin acute spines, the declivity on each side with a narrow carina.

Femoral gland bullae conspicuous on all legs.

Petiole node long and low, in profile its dorsum much longer than its anterior face but the posterior half of the dorsal outline obscured by an upper extension of the large lateral spongiform lobe. Dorsal length of petiole greater than length of postpetiole disc.

Spongiform appendages large on both petiole and postpetiole. Base of first gastral sternites with a thin arched-transverse crest of subspongiform tissue.

Pilosity. Pronotal humeral hair very long, flagellate. Flagellate hairs present on dorsum and dorsolateral margins of head, also on promesonotum, waist segments and first gastral tergite. Long simple to flagellate hairs project freely from dorsal (outer) surfaces of all tibiae and basitarsi, as well as elsewhere on legs. A row of paddle-shaped hairs arises from the dorsal margin of each mandible.

Sculpture. Punctate to reticulate-punctate sculpture present everywhere except on disc of postpetiole and first gastral tergite, which are smooth and shining.