Strumigenys luca

A well collected Strumigenys species that has been found in a wide range of forest habitats. Specimens have been found in litter, on the ground and in rotting wood.

Identification
Bolton (2000) - A member of the hilaris complex in the Strumigenys arnoldi-group. S. luca is most similar to Strumigenys milae in the hilaris-complex and can be easily distinguished from the latter species by the presence of a single pair of erect hairs on the mesonotum. See milae for further discussion.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  luca. Strumigenys luca Fisher, in Bolton, 2000: 663 (w.) MADAGASCAR.

Worker
Holotype. TL 3.1, HL 0.69, HW 0.59, CI 85, ML 0.37, MI 53, SL 0.46, SI 78, PW 0.33, AL 0.74. Characters of hilaris-complex. Each mandible with 2 preapical teeth, situated in the apical third; proximal preapical tooth longer than distal. Upper scrobe margin distinct but not bordered by a projecting laminar rim or flange throughout its length. Eyes moderate in size, convex, and plainly visible in full-face view; maximum diameter of eye distinctly greater than maximum width of scape. Scape short, more or less straight, widest in the mid section; hairs on leading edge fine, slightly flattened or spoon-shaped apically. Cephalic dorsum densely clothed with curved narrowly spatulate to flattened spatulate ground-pilosity; upper scrobe margin fringed with curved narrowly spatulate hairs. Cephalic dorsum with 4 stout standing hairs arranged in a transverse row close to the occipital margin and a more anteriorly situated pair on vertex. Pronotal humeral hair absent; humeral angles rounded, posterior lateral margin of pronotum bluntly marginate. Anterior margin of mesonotum with a pair of stout filiform hairs. Propodeum with one pair of short, fine, posteriorly curved hairs at anterior base of propodeal spines. Ground-pilosity on alitrunk as on head but sparser. Dorsum of alitrunk in outline convex anteriorly, posterior mesonotum gradually sloping down to metanotal groove. Anterior propodeum slightly raised above mesonotum; propodeum not flat, gradually sloping down to declivity. Propodeal spines narrowly triangular, subtended by a narrow lamella on declivity. Alitrunk dorsum and side of pronotum densely reticulate-punctate, portions of central pleurae often smooth and shiny. Petiole node in dorsal view about as broad as long. Postpetiole disc densely and finely reticulate-punctulate. Spongiform appendages of petiole absent; weakly developed on postpetiole. Spongiform collar present only on posterior margin of postpetiole. Basigastral costulae short and distinct, with secondary and much longer fine striolate sculpture arising between the shorter costulae. Dorsal surfaces of petiole, postpetiole and gaster with stout standing narrowly remiform hairs. Colour light to medium brown.

Paratypes. TL 2.8-3.1, HL 0.63-0.70, HW 0.53-0.61, CI 83-91, ML 0.35-0.38, MI 52-58, SL 0.43-0.49, SI 75-84, PW 0.32-0.35, AL 0.68-0.74 (9 measured). As holotype.

Measurements of this material extend the range shown by the type-series: HL 0.63-0.73, HW 0.53-0.58, CI 79-85, ML 0.34-0.40, MI 52-59, SL 0.44-0.48, SI 82-85 (5 measured). This material shows variation in the outline of the posterior portion of the alitrunk. In some specimens, the anterior margin of the propodeum is not raised above the mesonotum, and the propodeum is more or less flat.

Type Material
Holotype worker, Madagascar: Provo Toliara, southern Isoky-Vohimena Forest, 59 km. NE Sakaraha, 22°41'S, 44°50'E, 730 m., 21.i.1996, sifted litter (leaf mold, rotten wood), tropical dry forest #1312 (4)-3 (S. Razajimandimby).

Paratypes. 16 workers with same data as holotype but coded (1)-4, (2)-1, (3)-2, (5)-2, (7)-4, (8)-3, (18)-3, (25)-1, (28)-1, (30)-4, (36)-2, (46)-2,.

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.
 * Ravelomanana A., and B. L. Fisher. 2013. Diversity of ants in burned and unburned grassland, and dry deciduous forest in the Beanka Reserve, Melaky Region, western Madagascar. Malagasy Nature 7: 171-183.