Strumigenys grandidieri Forel

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 : 654

Strumigenys grandidieri Forel (Figs 393, 414)

Strumigenys grandidieri Forel , 1892 c: 517. Syntype worker, MADAGASCAR: Foret d'Andrangoloaka (Sikora) (MCZ) [examined].

[ Strumigenys grandidieri : Santschi, 1913 a: 259; W. M. Wheeler, 1922 a: 1034 and Emery, 1924: 320 (catalogues); Brown, 1954: 12 (redescription of worker); Bolton, 1995 b: 397 (catalogue).]

WORKER. TL 4.8 - 5.8, HL 1.25 - 1.45, HW 0.97 - 1.14, CI 76 - 80, ML 0.67 - 0.76, MI 52 - 57, SL 0.87 - 1.03, SI 89 - 93, PW 0.52 - 0.57, AL 1.26 - 1.49 (9 measured). Characters of grandidieri- complex. Mandibles almost straight and at full closure parallel. Apical fork of mandible with 2 spiniform teeth, without intercalary teeth or denticles. Mandible with 2 preapical teeth of similar size, short and truncated, situated in the apical third of the length; proximal preapical tooth occasionally reduced on left mandible. Upper scrobe margin ends, or at least becomes extremely indistinct, at about the level of the eye. Eye large, convex, and plainly visible in full-face view. Scape slender and subcylindrical, more or less straight, the leading edge with a row of fine hairs which are slightly flattened or spoon-shaped apically. Cephalic dorsum with curved narrowly spatulate ground-pilosity; hairs on upper scrobe margin are the same shape and size as those on the dorsum. Cephalic dorsum with 6 simple standing hairs arranged in a transverse row close to the occipital margin and a more anteriorly situated pair on vertex. Dorsum of head reticulate-punctate with superimposed rugulation. Pronotal humeri rounded, humeral hair absent. Anterior margin of mesonotum with a pair of stout filiform hairs. Ground-pilosity on alitrunk as on head but sparser. Dorsum of alitrunk in outline convex anteriorly, posterior mesonotum forming a long slope down to the metanotal groove, propodeal dorsum more or less flat. Anterior mesonotum with a distinct narrow carina above the mesothoracic spiracle. Propodeal spines narrowly triangular and almost spiniform, divergent; propodeal lamella absent. Alitrunk dorsum and sides densely reticulate-punctate, central katepisternum occasionally smooth and shiny. Fine rugulose sculpture present on alitrunk dorsum, most distinct on anterior pronotal margin. Petiole node in dorsal view reticulate-punctate and slightly longer than broad. Postpetiole disc reticulate-punctate. Spongiform appendages of petiole and postpetiole extremely reduced, spongiform collar present on disc of postpetiole. Basigastral costulae short and distinct, remainder of gaster smooth and shiny when clean. Petiole dordum without standing hairs. Dorsum of postpetiole with one pair of posterior projecting hairs. Dorsal surface of gaster with stout standing hairs. Colour yellowish brown to medium brown.

In this group grandidieri is the only species with truncated preapical mandibular teeth. Its large size and lack of a pronotal humeral hair also help identify the species.

MATERIAL EXAMINED

Madagascar: 25 km. NNE Ankazobe, 1500 m. (P. S. Vhrd); P. N. Mantadia 895 m. (H. J. Ratsirarson); Perinet (W. L. Brown); 7 km. W Ranomafana, 900 m. (WE. Sieiner); 7 km. W Ranomafana 1000 m. (GO Alpert); 8.0 km. E Ivohibe, R. S. Ivohibe 1200 m. (S. Razafimandimby); 13 km. NW Enakara, Res. Andohahela, 1250 m. (B. L. Fisher).