Strumigenys carisa

Identification
Bolton (2000) - A member of the carisa complex in the Strumigenys arnoldi-group. S. carisa and Strumigenys fronto belongs to the carisa-complex and are diagnosed by left and right mandible having a single preapical tooth and the pronotal humeral hair being long, stiffly projecting and filiform.

S. carisa can be distinguished from fronto by the absence on the upper scrobe margin of stiff erect hairs that are longer than the hairs on leading edge of scape. In addition carisa possesses a longer and relatively narrower head (HL 0.95-1.00, CI < 70) than fronto (HL 0.80-0.88, CI > 80).

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  carisa. Strumigenys carisa Fisher, in Bolton, 2000: 658 (w.) MADAGASCAR.

Worker
Holotype. TL 4.1, HL 0.98, HW 0.65, CI 66, ML 0.60, MI 61, SL 0.73, SI 112, PW 0.42, AL 1.04. Characters of carisa-complex. Each mandible with 1 preapical acute tooth, situated in the apical third of the length. Upper scrobe margin not bordered by a projecting laminar rim or flange throughout its length, eyes clearly visible in full-face view. Eye small, convex, its maximum diameter slightly greater than maximum width of scape. Scape long and slender, subcylindrical and approximately straight; hairs on leading edge narrowly spatulate. Cephalic dorsum densely clothed with curved narrowly spatulate ground-pilosity; upper scrobe margin fringed with hairs that are similar in size and shape to those on the dorsum. Cephalic dorsum with 2 pairs of long stout standing remiform hairs arranged in a transverse row close to the occipital margin; paratype and non-paratype with 1 additional pair of erect hairs near vertex. Dorsum of head reticulate-punctate and also with longitudinally rugulose sculpture, more pronounced on occipital angles. Pronotal humeral hair long, stout and filiform; humeral angles rounded. Mesonotum with 1 pair of stout standing narrowly spatulate hairs, on anterior margin. Ground-pilosity on alitrunk dorsum as on head but sparser. Dorsum of alitrunk in outline convex anteriorly, posterior mesonotum sharply depressed, propodeum more or less flat. Metanotal groove represented by a transverse ridge or carina. Propodeal spines narrowly triangular, diverging, lamella absent from declivity. Alitrunk dorsum densely reticulate-punctate. Promesonotal dorsum with superimposed striolate and rugulose sculpture. Sides of pronotum striolate to reticulate-punctate. Pleurae mostly reticulate-punctate, katepisternum partially smooth and shiny. Petiolar peduncle long and slender. Petiole node in dorsal view longer than broad. Postpetiole disc longitudinally striolate with faint punctures present on lateral margin. On paratype specimen, central area of postpetiole disc more or less smooth and shiny. In profile ventral spongiform tissue of petiolar peduncle a very narrow, irregular strip that is not continuous along the base of the peduncle, maximum depth of strip distinctly less than the maximum width of eye. Ventral spongiform lobe of postpetiole moderately developed. Basigastral costulae very short but distinct. Dorsal surface of petiole with one pair and postpetiole with 3 pairs of long, erect remiform to narrowly spatulate hairs, gaster with stout standing remiform to narrowly spatulate hairs. Colour light to medium brown.

Paratypes. TL 4.2, HL 1.00, HW 0.68, CI 68, ML 0.66, MI 66, SL 0.75, SI 110, PW 0.42, AL 1.07 (1 measured). As holotype.

Measurements of this specimen extend the range shown by the type-series: HL 0.95, HW 0.63, CI 66, ML 0.60, MI 63, SL 0.73, SI 115, PW 0.41, AL 1.01 (1 measured) but otherwise as type-specimens.

Type Material
Holotype worker, Madagascar: 9.2 km. WSW Befingotra, Res. Anjanaharibe-Sud, 14°45'S, 49°28'E, 1200 m., 9.xi.1994, sifted litter (leaf mold rotten wood), montane rainforest #1192 (26)-6 (B. L. Fisher).

Paratypes. 1 worker with same data as holotype but 5.xi.1994, 1280 m, #1158 (5)-5.

References based on Global Ant Biodiversity Informatics

 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.