Strumigenys gyges group

Strumigenys gyges group Bolton (2000)

Worker Diagnosis
Mandibles in full-face view and at full closure elongate-triangular; teeth occupy only the apical half of the mandible but engage through the lengths of the tooth rows. Basal halves edentate and with a large space between them, through which the labral lobes are visible. Close to the clypeus the dorsum of each mandible i s traversed by a weak oblique rim that meets the masticatory margin considerably proximal of the basal tooth. Inventral view outer margin of mandible with a weak prebasal inflection. MI 32-36.

Dentition. Basally with a dental row of 5 low, acute, triangular teeth, followed by 2 slightly shorter teeth, a row of 5 denticles, a preapical tooth that is almost as large as teeth 1-5, and an apical tooth that is markedly enlarged, broad-based, curved and acute, by far the longest and stoutest tooth on the margin. Total dental count 14.

Basal lamella an elongate, very narrow, laminate strip that follows the inner curvature of the mandible. The basal lamella is almost as long as the principal basal dental row but is very much lower than the basal tooth. Lamella visible in full-face view with the mandibles fully closed, terminating just before the basal tooth.

Labrum terminates in a pair of short triangular narrow lobes.

Clypeus with anterior margin broad, evenly shallowly convex across its width. Sides of clypeus proper very short, merging into the preocular ridge almost immediately behind the anterolateral angles.

Clypeal dorsum with minute appressed hairs, the clypeal margins with minute curved hairs; freely projecting specialised hairs do not occur anywhere on the sclerite.

Preocular carina conspicuous in full-face view.

Ventrolateral margin of head extremely poorly developed between eye and mandible, scarcely angular between side and ventre. Postbuccal impression small.

Cuticle of side of head within scrobe reticulate.

Scape short, SI 57-60, broadest at about the basal third and the leading edge rounded where the scape is broadest; proximal to this the scape suddenly narrowing to the base.

Leading edge of scape with 1-2 approximately straight anteriorly projecting hairs near the greatest curvature, the edge from this point to the apex with a row of small, spatulate hairs that curve toward the apex of the scape.

Pronotal dorsum without a median longitudinal carina.

Propodeum unarmed, without trace of spines or teeth but with a distinct narrow lamella that extends the full height of the declivity. Propodeum in profile with its dorsal outline high anteriorly, sloping steeply downward posteriorly.

Spongiform appendages of petiole and postpetiole reduced, small and inconspicuous. Base of first gastral sternite with a weakly developed narrow crest of spongiform tissue. Pilosity. Pronotal humeral hair absent. Erect hairs sparsely present on vertex and first gastral tergite, absent from dorsal surfaces of alitrunk and waist segments. Ground pilosity of head and pronotum of inconspicuous, minute curved hairs. Dorsal (outer) surfaces of middle and hind tibiae with minute apically directed hairs, without elongate freely projecting pilosity.