Strumigenys mitis group

Strumigenys mitis group Bolton (2000)

Worker Diagnosis
Mandibles in full-face view and at full closure subtriangular, serially dentate; masticatory margins engage throughout their visible length. In ventral view outer margin of mandible without an inflected prebasal angle. MI 12-20.

Dentition. Basally with a dental row of 7 small, acutely triangular teeth, the first 5 about equal in length and slightly taller than 6 and 7. Tooth 7 followed by 5 minute denticles, a slightly larger preapical tooth and an apical tooth that is slightly larger than the members of the principal basal row. Total dental count 14.

Basal lamella of mandible an elongate, shallowly rounded subtriangular lobe along the predentary margin. It is narrowest proximally, broadest where it abuts the basal tooth, but at its apex is lower than the basal tooth and is not separated from it by a diastema. Basal lamella not visible in full-face view when mandibles fully closed.

Labrum terminates in a pair of short narrow lobes that are subconical to digitate.

Clypeus with anterior margin narrowly convex. On each side of the anteriormost point the margin is strongly posteriorly divergent. Outer margins of mandibles in full-face view are outside the clypeal margin from its apex to its anterolateral angles.

Clypeal dorsum and margins without standing or projecting pilosity of any form.

Preocular carina with only extreme lateral edge visible in full-face view between posterior margin of clypeus and level of posterior frontal lobe.

Ventrolateral margin of head angular between eye and base of mandible. Postbuccal impression very shallow and inconspicuous.

Cuticle of side of head within scrobe finely reticulate to smooth.

Scape short to moderate, SI 63-75. Leading edge not expanded into a flattened rim or projecting flange-like edge.

Leading edge of scape lacking prominent hairs, the scape shaft narrow and only very feebly curved basally.

Head in full-face view with the dorsolateral margins approximately straight, gradually evenly divergent posteriorly from the frontal lobes to the widest point of the occipital lobes; without broadly convex or abruptly divergent margins behind the level of the frontal lobes.

Pronotal dorsum more or less flat but not marginate dorsolaterally and lacking a median longitudinal carina.

Propodeum without trace of spines or teeth, the declivity with a very broad lamella that extends its entire depth and has a convex posterior (free) margin. In profile the lamella at its broadest is at least equal to the dorsal length of the petiole node (excluding the posterior collar).

Spongiform appendages of petiole and postpetiole large and well developed. Base of first gastral sternite without dense spongiform tissue.

Pilosity. Pronotal humeral hair absent. Dorsal surfaces of head and body without standing pilosity of any form. Freely projecting hairs also absent from dorsolateral margins of head and dorsal (outer) margins of leg segments. Ground-pilosity minute, very inconspicuous on head and alitrunk.