Strumigenys dicomas 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 : 655-656

Strumigenys dicomas Fisher sp. n. (Figs 394, 416)

HOLOTYPE WORKER. TL 3.6, HL 1.01, HW 0.93, CI 93, ML 0.48, MI 47, SL 0.63, SI 67, PW 0.42, AL 0.86. With the above characters and the following. Outer margins of mandibles shallowly convex in full-face view. Upper scrobe margin bordered by a conspicuous laminate rim or flange throughout its length; eyes partially visible in full-face view. Leading edge of scape with a row of slender hairs which are slightly flattened or spoon-shaped apically. Cephalic dorsum clothed with inconspicuous small curved spatulate to narrowly spoon-shaped ground-pilosity; the upper scrobe margin fringed with hairs which are similar in shape and size as those on the dorsum; apicoscrobal hair absent. Cephalic dorsum with 6 simple standing hairs arranged in a transverse row close to the occipital margin; many paratypes have a more anteriorly situated pair near the highest point of the vertex. Dorsum of head reticulate-punctate, middorsum rugulose in larger specimens. Mesonotum with a single pair of stout standing hairs situated on anterior margin. Propodeum without a pair of short, fine, posteriorly curved hairs immediately anterior of propodeal spines. Ground-pilosity on alitrunk as on head but sparser. With the alitrunk in profile the posterior portion of the mesonotum sharply depressed, the metanotal groove represented by a shallow impression. Pronotal humeri rounded. Dorsolateral margin of posterior pronotum bluntly marginate. Anterior mesonotum with a distinct narrow carina above the mesothoracic spiracle. Propodeal spine long and slender, recurved, especially near the apex; propodeal lamella absent. Alitrunk dorsum reticulate-punctate; lateral margins of pronotum rugulose; pleurae more or less smooth centrally with peripheral reticulate-punctate sculpture. Petiole node in dorsal view finely reticulate-punctate, exposed area of cuticle slightly broader than long. Postpetiole superficially reticulate-punctate. Spongiform appendages of petiole weakly developed, with a narrow ventral curtain. Postpetiole with small but distinct lateral and ventral spongiform lobes. Basigastral costulae short and distinct; gaster smooth and shiny when clean. Dorsal surfaces of petiole, postpetiole, and gaster with stout standing hairs which are swollen apically. Colour dull yellow to light medium brown.

PARATYPE WORKERS. TL 3.6 - 4.2, HL 1.00 - 1.17, HW 0.91 - 1.11, CI 90 - 95, ML 0.48 - 0.55, MI 46 - 49, SL 0.62 - 0.70, SI 63 - 68, PW 0.41 - 0.49, AL 0.81 - 1.02 (9 measured). As holotype.

Holotype worker, Madagascar: 9.2 km. WSW Befingotra, Res. Anjanaharibe-Sud, 14 ° 45 ' S, 49 ° 28 ' E, 1200 m., 9. xi. l 994, sifted litter (leaf mold rotten wood), montane rainforest # 1192 (12) - 14 (B. L. Fisher) (MCZ). Paratypes. 9 workers and 2 queens (dealate) with same data as holotype but coded (3) - 9, (23) - 9, (24) - 9, (24) - 10, (29) - 8, (36) - 9, (40) - 4, (50) - 10, (L. O.) - IO (BMNH, SAM).

NON-PARATYPIC MATERIAL EXAMINED. Madagascar: R. S. Manongarivo, 10.8 km. 229 ° SW Antanambao, 400 m. (B. L. Fisher); R. S. Manongarivo, 12.8 km. 228 ° SW Antanambao, 780 m. (B. L. Fisher); R. S. Manongarivo, 14.5 km. 220 ° SW Antanambao, 1175 m. (B. L. Fisher); 9.2 km. WSW Befingotra, Res. Anjanaharibe-Sud, 1280 m. (B. L. Fisher); RNI Marojejy, 375 m., 665 m. (G. D. Alpert); 55 km. S Antalaha, Nosy Ngontsy, 1 m. (Alpert ei al.); 19 km. ESE Maroantsetra, 350 m. (P. S. Ward); 5.3 km. SSE Ambanizana, Andranobe, 425 m. (B. L. Fisher); 6.9 km. NE Ambanizana, 825 m. (B. L. Fisher); Nosy Mangabe, 20 m. (P. S. Ward); S. F. Tampolo, 10 m. (B. L. Fisher); Causse de Kelifely (A. Peyrieras); Route d'Andriamena (A. Peyrieras); Foret d'Andranobe, Road to Andriamena 1200 m. (J. - M. Betsch); F. C. Sandranantitra 450 m. (H. J. Ratsirarson); F. C. Didy 960 m. (H. J. Ratsirarson); F. C. Andrianantantely 530 m. (H. J. Ratsirarson); P. N. Mantadia 895 m. (H. J. Ratsirarson); Perinet (W. L. Brown); Andasibe, 870 m. (Alpert et al.); For. d'Ambatofitorahana 293 - 294 km. on route national no. 7, 1800 m. (J. - M. Betsch); 3 km. W Ranomafana, 950 m. (P. S. Ward); Ranomafana Nat. Park, Maharira Forest, 1130 m. (E. Rajeriarison); Ranomafana Nat. Park Andranobe, Vohiparara Forest, 1160 m. (E. Rajeriarison); 45 km. S Ambalavao, 785 m. (B. L. Fisher); 11 km. NW Enakara, Res. Andohahela, 800 m. (B. L. Fisher).

The non-paratypic material shows greater size variation than the type-series alone: HL 0.86 - 1.09, HW 0.75 - 1.04, CI 87 - 95, ML 0.41 - 0.52, MI 42 - 50, SL 0.53 - 0.68, SI 61 - 75 (12 measured), but otherwise matches all diagnostic characters.

S. dicomas is widely distributed but easily recognized. In the Malagasy region it is the only species with mandible shape and dentition as described in the diagnosis above.