Strumigenys admixta

This species has been found in a range of forest habitats and sampled from leaf litter, rotten wood, and under a stone.

Identification
Bolton (2000) - A member of the sphera complex in the Strumigenys arnoldi-group. S. admixta can be isolated from other members of the sphera-complex by the following characters:

1 Upper scrobe margin with a projecting lamellate flange throughout its length.

2 Basal half of scape distinctly and sharply swollen; in dorsal view maximum width of scape about twice its apical width.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

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

Worker
Holotype. TL 2.5, HL 0.65, HW 0.58, CI 90, ML 0.32, MI 49, SL 0.42, SI 72, PW 0.31, AL 0.62. Characters of sphera-complex. Each mandible with 1 preapical acute tooth which is situated in the apical third of the length. Upper scrobe margin with a projecting lamellate flange throughout its length, eyes not visible in full-face view. Eye small, convex, its maximum diameter less than maximum width of scape. Basal portion of scape swollen, apical third subcylindrical; hairs on leading edge fine, narrowly spatulate. Cephalic dorsum densely clothed with small appressed scale-like ground-pilosity; upper scrobe margin fringed with short curved narrowly spatulate to spoon-shaped hairs. Cephalic dorsum with 3 pairs of stout standing remiform to clavate hairs arranged in a transverse row close to the occipital margin, and 1 pair on vertex. Pronotal humeral hair absent, the humeral angles bluntly marginate. Mesonotum with 1 pair of stout standing clavate hairs, on anterior margin. Ground-pilosity on alitrunk dorsum sparse, consisting of short narrowly spatulate to broadly spatulate (almost scale-like) hairs. Dorsum of alitrunk in outline convex anteriorly, posterior portion more or less flat to gently sloping to declivity. Metanotal groove shallowly impressed. Propodeal spines narrowly triangular, diverging; lamella absent from declivity. Alitrunk dorsum densely reticulate-punctate. Pronotal dorsum with superi mposed rugulose sculpture, most evident at lateral margins. Sides of pronotum striolate to costulate with punctate sculpture on apical margin, remainder more or less smooth. Pleurae smooth and shiny with punctures peripherally. Petiole node in dorsal view approximately as broad as long. Postpetiole disc reticulate-punctate, on some specimens faint longitudinally striolate sculpture present on lateral margins of disc. In profile ventral spongiform tissue of petiolar peduncle a narrow curtain along the base of the peduncle, depth of curtain approximately equal to maximum width of eye. Ventral spongiform lobe of postpetiole moderately developed. Basigastral costulae short but distinct. Dorsal surface of petiole with one pair of erect stout clavate hairs; postpetiole and gaster with stout standing clavate hairs. Colour light to medium brown.

Paratypes. TL 2.6-2.7, HL 0.67-0.71, HW 0.58-0.62, CI 84-91, ML 0.33-0.36, MI 49-50, SL 0.44-0.46, SI 71-78, PW 0.32-0.34, AL 0.63-0.68 (6 measured). As holotype.

Measurements of this material extend the range shown by the type-series: HL 0.64-0.69, HW 0.55-0.61, CI 82-90, ML 0.31-0.34, MI 46-52, SL 0.40-0.44, SI 70-79 (7 measured).

Type Material
Holotype worker, Madagascar: 5.3 km. SSE Ambanizana, Andranobe, 15°40'S, 49°58'E, 425 m., 21.xi.1993, sifted litter (leaf mold, rotten wood), rainforest, #926 (1)-6 (B. L. Fisher).

Paratypes. workers with same data as holotype but coded (10)-7, (27)-9, (28)-11, (35)-10, (40)-16. .

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.