Strumigenys actis 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 : 648-649

Strumigenys actis Fisher sp. n.

HOLOTYPE WORKER. TL 3.4, HL 0.88, HW 0.70, CI 80, ML 0.46, MI 52, SL 0.59, SI 84, PW 0.36, AL 0.85. Characters of chilo-complex. Mandibles almost straight and at full closure parallel. Apical fork of mandible subtended by a third, shorter spiniform tooth, the fork effectively 3 - dentate; without intercalary teeth or denticles. Preapical teeth absent. Upper scrobe margin ends, or at least becomes extremely indistinct, at about the level of the eye; when viewed in profile upper scrobe margin extends posteriorly across dorsal apex of vertical preocular groove of side of head; preocular groove meets and is interrupted by the upper scrobe margin before reaching the cephalic dorsum. Eye large, convex, and plainly visible in full-face view. Scape long and slender, approximately straight, the leading edge with a row of slender hairs which are slightly flattened or spoon-shaped apically. Cephalic dorsum densely clothed with curved spoon-shaped ground-pilosity; the upper scrobe margin without a row of hairs. Cephalic dorsum with 4 simple standing hairs arranged in a transverse row close to the occipital margin. Dorsum of head reticulatepunctate. Mesonotum with a single pair of stout standing hairs situated on anterior margin. Propodeum with one 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. Lateral margin of posterior pronotum bluntly marginate. Anterior mesonotum with a narrow carina above the mesothoracic spiracle. Propodeal tooth long and slender, almost spiniform; propodeal lamella absent. Alitrunk dorsum and sides reticulate-punctate. Petiole node in dorsal view reticulate-punctate and much longer than broad. Postpetiole disc reticulate-punctate. Spongiform appendages of petiole weakly developed. Postpetiole with small but distinct lateral and ventral spongiform lobes. Basigastral costulae fine across base of gaster without a central clear area; gaster smooth and shiny where clean. Dorsal surfaces of petiole often with a pair of short posteriorly projecting hairs; postpetiole with a pair of posteriorly projecting stout hairs; gaster with stout standing hairs which are weakly swollen apically. Colour dull yellow to light medium brown.

Holotype worker, Madagascar: 43 km. S Ambalavao, Res. Andringitra, 22 ° 14 ' S, 47 ° 00 ' E> 825 m., 5. x. 1993, sifted litter (leaf mold rotten wood), rainforest # 747 (14) - 8 (B. L. Fisher) (MCZ).

NON-PARATYPIC MATERIAL EXAMINED. Madagascar: Perinet, 900 m., (J. - M. Belsch); Ranomafana Nat. Park, Vohiparara Forest, 1160 m. (E. Rajeriarison); Pare Nat. de Ranomafana (Bartolozzi el at.); Ranamafana Nat. Park, 1040 m. (WE. Steiner); 7 km. W Ranomafana, 900 m. (WE. Sleiner); 3 km. W Ranomafana, 950 m. (P. S. Wjrd); 7.5 km. ENE Ivohibe, 900 m. (S. Razqfimandimby); 9.0 km. NE Ivohibe, 900 m. (S. Razafimandimby).

Measurements of this material extend the range shown by the type-series: TL 3.3 - 3.9, HL 0.86 - 1.01, HW 0.65 - 0.86, CI 75 - 92, ML 0.44 - 0.54, MI 49 - 59, SL 0.56 - 0.70, SI 79 - 86, PW 0.34 - 0.41, AL 0.80 - 0.99 (9 measured).

Among the Malagasy species that have the mandibular apical fork subtended by a shorter third tooth actis is easily isolated by the following characters:

1 Upper scrobe margin ends, or at least becomes extremely indistinct, at about the level of the eye; when viewed in profile, upper scrobe margin extends posteriorly across dorsal apex of vertical preocular groove of side of head; preocular groove meets and is interrupted by the upper scrobe margin before reaching the cephalic dorsum.

2 Mesonotum with 1 pair of erect hairs, on anterior margin.

3 Cephalic dorsum with a transverse row of four erect hairs immediately in front of occipital margin.