Strumigenys diota 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 : 676-677

Strumigenys diota Fisher sp. n. (Fig. 400)

HOLOTYPE WORKER. TL 2.9, HL 0.67, HW 0.45, CI 67, ML 0.38, MI 57, SL 0.52, SI 115, PW 0.28, AL 0.76. Characters of diota-complex. Mandibles in full-face view with outer margins shallowly and evenly convex, width approximately constant from the level of the proximal preapical tooth to near the base. Upper scrobe margins evenly diverging posteriorly, shallowly convex, not bordered by a rim or flange, the eyes clearly visible in full-face view. Maximum diameter of eye about equal to or slightly greater than maximum width of scape, with 4 - 5 ommatidia in longest row. Scape long, slender and subcylindrical, only very feebly curved near base; hairs on leading edge small and slender, slightly flattened or spoon-shaped apically. Cephalic dorsum densely clothed with short broad flattened hairs which appear scale-like to spatulate in full-face view. The upper scrobe margin fringed with a row of hairs which are the same as those on the dorsum and about equal in size to those on the leading edge of the scape. Cephalic dorsum with 6 standing remiform to clavate hairs arranged in a transverse row of 4 close to the occipital margin and a more anteriorly situated pair. Pronotal humeral hair absent; humeral angles rounded. Anterior margin of mesonotum with a pair of stout clavate hairs. Propodeum with a pair of narrow spatulate hairs immediately anterior of propodeal spines. Ground-pilosity of dorsal alitrunk of short curved broadly spatulate hairs which decrease in density posteriorly on the propodeum. Dorsum of alitrunk in outline convex anteriorly and more or less flat posteriorly; posterior portion of mesonotum slightly depressed below the anterior margin of propodeum. Anterior mesonotum with a narrow carina above the mesothoracic spiracle. Propodeal tooth broadly triangular and pointed apically; lamella on declivity narrow. Alitrunk dorsum and sides reticulate-punctate. Disc of postpetiole conspicuously broader than long, shiny with longitudinally carinate sculpture. Ventral spongiform tissue of petiole and postpetiole moderately developed. Petiole with a weakly developed lateral lobe. Lateral lobe of postpetiole, in dorsal view, only very slightly projecting beyond the lateral outline of the disc. Base of first gastral tergite with sharply defined costulae radiating on each side of a broad central clear area. Dorsal surfaces of petiole, postpetiole and gaster with standing remiform to broadly clavate hairs which are thickened apically. Colour dull yellowish brown.

PARATYPE WORKERS. TL 2.5, HL 0.57, HW 0.39, CI 68, ML 0.31, MI 55, SL 0.43, SI 111, PW 0.24, AL 0.62 (1 measured). As holotype.

Holotype worker, Madagascar: 6.5 km. SSW Befingotra, Res. Anjanaharibe-Sud, 14 ° 45 ' S, 49 ° 30 ' E, 875 m., 19. x. 1994, sifted litter (leaf mold rotten wood), rainforest # 1070 (42) - 20 (B. L. Fisher) (MCZ). Paratype. 1 worker with same data as holotype but coded (4) - 9 (BMNH).

S. diota is distinguished from other Malagasy species of the scotti-group by having the pronotal humeral hair absent and the inner margin of mandible without a translucent lamina. The narrow and relatively long mandibles and long scapes also help identify this species.