Strumigenys vazimba Fisher, 2000

Bolton, B., 2000, The ant tribe Dacetini. With a revision of the Strumigenys species of the Malgasy Region by Brian L. Fisher, and a revision of the Austral epopostrumiform genera by Steven O. Shattuck., Memoirs of the American Entomological Institute 65, pp. 1-1028 : 669-670

Strumigenys vazimba Fisher sp. n. (Figs 399, 419)

HOLOTYPE WORKER. 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 groundpilosity; 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 1 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 broader 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.

PARATYPE WORKERS. 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.

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) (MCZ).

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

NON-PARATYPIC MATERIAL EXAMINED. Madagascar: 6.5 km. SSW Befingotra, Res. Anjanaharibe-Sud, 875 m. (B. L. Fisher); 17 km. W Andapa, Res. Anjanaharibe-Sud, 875 m. (G. D. Alpert); 9.2 km. WSW Befingotra, Res. Anjanaharibe-Sud, 1200 m. (B. L. Fisher); 5.3 km. S Ambanizana, Andranobe, 425 m. (B. L. Fisher); 6.9 km. NE Ambanizana, 825 m. (B. L. Fisher); Andranobe, Route d'Andriamena, (A. Peyrieras); F. C. Andrianantantely, 530 m. (H. J. Raisirarson); F. C. Sandranantitra, 450 m. (H. J. Ratsirarson); 43 km. S Ambalavao, Res. Andringitra, 825 m. (B. L. Fisher); 45 km. S Ambalavao, 785 m. (B. L. Fisher); 9.0 km. NE Ivohibe, 900 m. (S. Razafimandimby); 8.0 km. E Ivohibe, R. S. Ivohibe 1200 m. (S. Razafimandimby); 10 km. NW Enakara, Res. Andohahela, 430 m. (B. L. Fisher).

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.

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 loriae (HW 1.60) and the Neotropical godmani (HW 1.24). In Madagascar is approached only by 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.