Strumigenys weberi group

Strumigenys weberi group Bolton (2000)

Worker Diagnosis
Mandibles in full-face view and at full closure short triangular, with serially dentate masticatory margins that engage throughout their visible length; sometimes a few basalmost teeth may meet without fully interlocking. In ventral view outer margin of mandible without an inflected prebasal angle. MI 7-13.

Dentition. Basally with a dental row of 5 spiniform teeth of varying size, sometimes with a short diastema between basal lamella and basal tooth. Following the basal row are 2 shorter teeth, 4 minute denticles and a small apical tooth, giving a total dental count of 12.

Basal lamella of mandible a high truncated triangle or a high narrow rectangle with concave sides; not visible in full-face view with the mandibles fully closed.

Labrum terminates in a pair of triangular to digitate narrow lobes.

Clypeus with anterior margin varying from extremely shallowly evenly concave to very shallowly evenly convex, usually appearing roughly transverse at low magnifications. Sides of clypeus approximately straight, almost parallel or weakly convergent anteriorly in full-face view. Outer margins of mandibles intersect anterior clypeal margin at or very near to the anterolateral corners. In ventral view the lateral clypeal margins extend well beyond the outer margins of the fully closed mandibles through the basal third or more of their length.

Clypeus with lateral margins fringed with filiform to wire-like setae that are usually curved, upcurved or sinuate and are often blunt, truncated or weakly clavate apically, but which do not form an orderly row. Clypeal dorsum with simple to wire-like standing hairs that may be straight, curved or angled, and may be acute, truncated or clavate apically.

Preocular carina visible in full-face view but in some species very narrow so that only its lateral edge can be seen.

Ventrolateral margin of head between eye and mandible bluntly to sharply angular. Postbuccal impression varying from small and shallow to broad and distinctly concave.

Cuticle of side of head within scrobe sculptured.

Scape short to moderate, SI 65-78, dorsoventrally flattened, the dorsum and ventre converging anteriorly so that the leading edge is a flange or even a thin lamella.

Ventral surface of scape behind the leading edge usually distinctly concave.

Leading edge of scape with numerous freely projecting simple to wiry hairs that are wavy, curved, angled or hooked apically; hairs may be directed apically, basally, or anterodorsally.

Pronotum without a median longitudinal carina that is distinctly differentiated from the other sculpture.

Propodeum bidentate to bispinose, lamella on declivity very narrow to absent.

Spongiform appendages of waist segments strongly to massively developed. Limbus spongiform behind postpetiole. Base of first gastral sternite in profile without a pad of spongiform tissue.

Pilosity. Lateral margins of head in full-face view with abundant projecting simple pilosity that may be curved, angled or wavy. The hairs are simple to wire-like, apically acute, truncated or looped. At least 10 (frequently more) hairs project beyond the margin on each side between frontal lobe and occipital corner. All hairs of similar structure, without markedly different or conspicuously specialised pairs on the margin. Pronotal humeri without specialised hairs that are distinctly differentiated from the other pilosity of the dorsal alitrunk. Dorsal surfaces of promesonotum and gaster with numerous to abundant simple hairs that may be curved, wavy, twisted, looped or short-flagellate; pilosity extremely sparse or absent on propodeal dorsum. Ground-pilosity on head and alitrunk of small simple curved hairs, scattered among the main pilosity and often indistinct. Dorsal (outer) surfaces of middle and hind tibiae with suberect to decumbent fine simple hairs that are usually distinctly curved.

Sculpture. Dorsal surfaces of head and promesonotum strongly sculptured, usually strikingly so. Dorsum of head behind clypeus usually finely irregularly densely reticulate-rugulose, at least posteriorly; promesonotum usually coarsely longitudinally rugose or sulcate. Basigastral costulae strongly developed, sharp and dense.