Strumigenys nitens group

Strumigenys nitens group Booher et al. 2019.

A small group of endemic Caribbean species. There is one specimen record from the Bahamas with the remainder from Cuba and Hispaniola. Interestingly, no nitens group species are known from two other large Caribbean islands, Puerto Rico and Jamaica, but this may simply be due to a lack of litter sampling for ants on these islands.

Species

Neotropical

• Strumigenys caiman
• Strumigenys convexiceps
• Strumigenys hubbewatyorum
• Strumigenys nitens
• Strumigenys zemi

Key to Strumigenys nitens group

Worker Diagnosis

Booher et al. (2019) - Mandibles in full-face view and at full closure triangular to elongate-triangular, strongly tapering apically. Either extreme apices of mandibles alone engage, in which case a broad sub ovate gap is present between them, or apices of basal teeth more closely approximated. In profile mandible narrowing basally, the dorsal surface sloping down ward where it passes beneath the clypeus. In ventral view curvature of mandible continuous from apex to base. MI 26-39.

Dentition. Inner mandibular margin preapically with 2-3 small teeth in full-face view; apices of the basal one or two do not meet at full closure. Distal to these with a strongly down-curved to more or less vertical series of 4-6 teeth, the uppermost two longer and spiniform, the lower 2-4 shorter and triangular, with a total dental count of 6-9.

Basal lamella with an oblique anterior margin that is visible in full-face view with mandibles fully closed; the oblique margins form a pair of sloping edges that diverge from the midpoint of the anterior clypeal margin.

Labrum terminates in a pair of very broad flat lobes that are truncated apically.

Clypeus with anterior margin broad, transverse to extremely shallowly concave across its width. Lateral margins of clypeus very short but strongly convex, posteriorly with a distinct notch between clypeus and frontal lobe. In full-face view outer margins of mandibles intersect the anterior clypeal margin at or very close to the clypeal anterolateral angles, the lateral clypeal margins bulging out behind this.

Clypeal dorsum with minute appressed hairs only; lateral and anterior clypeal margins without projecting hairs of any form.

Frontal lobes and anterior portions of frontal carinae strongly expanded laterally; in full-face view their outer margins not distinctly divergent posteriorly and continuous with the lateral margins of the occipital lobes.

Preocular carina not visible in full-face view, completely overhung and concealed by the expanded frontal lobe and frontal carina.

Ventrolateral margin of head not marginate immediately in front of eye but sharp margination commences on posterior border of postbuccal impression, describes a high arch whose apex is higher than the level of the eye, then continues down and forward to base of mandible. Postbuccal impression narrow and very deeply incised.

Cuticle on side of head within scrobe mostly smooth, with some faint punctulate sculpture on lower half of scrobe in front of level of eye.

Scape short, SI 59-61, not dorsoventrally flattened, without a strongly defined subbasal angle.

Leading edge of scape with minute appressed hairs that are all directed toward the apex of the scape.

Pronotal dorsum without dorsolateral margination.

Propodeum in profile with a pair of triangular teeth. Immediately below the tooth the lamella is interrupted by the broad annulus of the propodeal spiracle that is markedly shifted posteriorly.

Spongiform appendages present on petiole and postpetiole. Base of first gastral sternite in profile with a pad of spongiform material.

Pilosity. Pronotum humeral hair simple or flagellate. Apicoscrobal hair curved, simple. Dorsal (outer) surfaces of middle and hind tibiae with apically curved short fine decumbent hairs.

Sculpture. Dorsum of head behind clypeus not reticulate-punctate. Alitrunk without sculpture, smooth and shining both dorsally and laterally. Disc of postpetiole smooth and shining.

Notes

A small group of Caribbean species, including recently discovered species from Hispaniola that are the first endemic species in the genus to be found on the island.

References

• Booher, D.B., Prebus, M.M., Lubertazzi, D. 2019. A taxonomic revision of the Strumigenys nitens and simulans groups (Hymenoptera: Formicidae), two Caribbean radiations of leaf litter ants. Zootaxa. 4656, 335-358. doi:10.11646/zootaxa.4656.2.7
• Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028.