Strumigenys ogloblini group

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Strumigenys ogloblini group Bolton (2000)

Species

Neotropical-Nearctic

Worker Diagnosis

Apical fork of mandible with one intercalary denticle. Mandible with a single spiniform preapical tooth located in the apical third; no proximal denticle. Inner margin of mandible proximal of preapical tooth shallowly convex. MI 51-52.

Leading edge of scape with a row of spatulate hairs, most of which are curved toward the base of the scape. Scape with a shallow subbasal bend, broadening to about the midlength and thereafter tapering to the apex.

Head in full-face view with broadly laminate translucent upper scrobe margin that at maximum is almost or quite as broad as the maximum width of the scape.

Ventrolateral margin of head not constricted in front of eye.

Propodeum with a pair of triangular teeth subtended by a very broad lamella on the declivity, margin of lamella concave immediately below tooth but thereafter broadly convex; without a sharp tooth or spine at base of declivity.

Petiole with peduncle bicarinate dorsally; node in profile subtriangular, in dorsal view much broader than long. Ventral surface of petiole with a deep and very dense curtain of spongiform tissue. Lateral spongiform lobe of petiole and lateral and ventral lobes of postpetiole large and dense. Base of first gastral sternite with a thick spongiform pad.

Pilosity. Pronotal humeral hair flagellate. Ground-pilosity of head and alitrunk of small spatulate hairs, some on posterior vertex longer and more elevated. Small hairs that project laterally from the upper scrobe margin in full-face view spoon-shaped, the anterior 3-4 curved anteriorly, the rest (apparently 7-9) curved posteriorly. Apicoscrobal hair flagellate. First gastral tergite with many long fine curved hairs that may be looped or narrowly flagellate at extreme apices.

Sculpture. Head and alitrunk reticulate-punctate; pleurae may have a smooth area. Disc of postpetiole smooth medially, feebly sculptured peripherally. First gastral tergite entirely smooth except for basigastral costulae.

Notes

The single species isolated here, Strumigenys ogloblini, does not fit comfortably in any other group. Brown (1958e) initially grouped it with Strumigenys perparva as the mandibles look similar and both species have posteriorly curved hairs fringing the upper scrobe margin. However, unlike ogloblini, perparva lacks intercalary denticles in the mandibular apical fork, and lacks ventral spongiform tissue on the petiole. The current compromise of isolating odd taxa in single-species groups, perforce adopted several times in the survey of this genus, is unsatisfactory but is the best that can be achieved until a proper cladistic analysis can be undertaken.

References