Strumigenys vazimba

Collected many times from litter-samples made from a range of wet forest habitats.

Identification
Bolton (2000) - The only member of the vazimba complex in the Strumigenys arnoldi-group. S. vazimba is unmistakable. It is one of the largest known species of Strumigenys in the world (HW 1.28-1.65), approached only by larger individuals of the Malesian polymorphic species Strumigenys loriae (HW 1.60) and the Neotropical Strumigenys godmani (HW 1.24). In Madagascar is approached only by Strumigenys grandidieri (HW 0.97-1.14). The presence of only 1 preapical tooth and/or denticle on left mandible blade, the greatly expanded laminar flange along the length of the upper scrobe margin, divergent and recurved propodeal spines, and the alitrunk dorsum without erect hairs, also characterise this species.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  vazimba. Strumigenys vazimba Fisher, in Bolton, 2000: 669, figs. 399, 419 (w.) MADAGASCAR.

Worker
Holotype. TL 5.4, HL 1.51, HW 1.44, CI 95, ML 0.70, MI 46, SL 0.92, SI 64, PW 0.61, AL 1.29. Characters of vazimba-complex. Mandibles robust, almost straight, at full closure diverging apically. Each mandible with 1 preapical blunt tooth which is situated in the apical third of the length. Upper scrobe margin with a greatly expanded lamellate flange throughout its length, eyes not visible in full-face view. Eye small, convex, maximum diameter of eye less than maximum width of scape. Scape widest in midsection of basal half, curved in apical third; hairs on leading edge fine, narrowly spatulate. Cephalic dorsum with short curved narrowly spatulate to spoon-shaped ground-pilosity; upper scrobe margin fringed with hairs similar in size and shape as those on the dorsum. Cephalic dorsum with 3 pairs (some paratypes with 4 pairs) of stout standing narrowly spatulate hairs arranged in a transverse row close to the occipital margin, and I pair on vertex. Dorsum of head reticulate-punctate and with superimposed rugulose sculpture. Pronotal humeral hair absent; dorsal alitrunk without erect hairs. Humeral angles rounded, posterior lateral margin of pronotum marginate and often with a raised welt. Propodeum with two pairs of short, narrowly spatulate posteriorly curved hairs at anterior base of propodeal spines. Alitrunk dorsum with short curved spatulate ground-pilosity. Dorsum of alitrunk in outline convex anteriorly, posterior portion of mesonotum sharply depressed, posterior alitrunk more or less flat. Metanotal groove shallowly impressed. Anterior margin of mesonotum raised above pronotum, forming a transverse arched lip across dorsum. Anterior mesonotum with a narrow projecting rim above the mesothoracic spiracle. Propodeal spines narrow, almost spiniform, diverging, strongly elevated and recurved anteriorly; lamella absent from declivity. Pronotal dorsum striolate-punctate to rugulose-punctate with anterior margin without punctures or with a fine punctulate surface. Sides of pronotum striolate to costulate with punctate sculpture on apical portion and more or less smooth or finely punctulate on basal half. Mesonotum and propodeum densely reticulate-punctate. Pleurae with reticulate-punctulate sculpture which is faint or effaced on central pleurae. Petiole node in dorsal view with superficial rugulose sculpture on a fine reticulate-punctulate surface, slightly b roader than long. Postpetiole disc with faint longitudinally striolate sculpture on a finely punctulate surface. In profile ventral spongiform tissue of petiolar peduncle a well developed curtain along the base of the peduncle, depth of strip distinctly greater than maximum width of eye. Ventral spongiform lobe of postpetiole moderately developed. Basigastral costulae dense and distinct, interspersed with longer faint striolate sculpture. Dorsal surface of petiole with one pair of erect stout remiform hairs; postpetiole and gaster with stout standing remiform hairs. Colour light to medium brown.

Paratypes. TL 4.9-6.0, HL 1.37-1.66, HW 1.28-1.65, CI 93-101, ML 0.65-0.72, MI 43-48, SL 0.86-1.04, SI 62-68, PW 0.53-0.67, AL 1.13-1.44 (7 measured). As holotype.

Measurements of this material extend the range shown by the type-series: HL 1.32-1.45, HW 1.28-1.41, CI 95-101, ML 0.61-0.69, MI 46-50, SL 0.83-0.92, SI 64-69 (6 measured). In some specimens from Ivohibe, disc of postpetiole more or less smooth but otherwise match all characters of type-series.

Type Material
Holotype worker, Madagascar: 6.3 km. S Ambanizana, Andranobe, 15°41'S, 49°57'E, 25 m., 14.xi.1993, sifted litter (leaf mold, rotten wood), rainforest, #886 (4)- 11 (B. L. Fisher).

Paratypes. 7 workers with same data as holotype but coded (21)-14, (13)-12, (46)-11, (30)-7, (34)-10, (43)-7.

References based on Global Ant Biodiversity Informatics

 * Blaimer B. B., S. G. Brady, T. R. Schultz, and B. L. Fisher. 2015. Fucntional and phylogenetic approaches reveal the evolution of diversity in a hyper diverse biota. Ecography 38: 001-012.
 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.