Tetraponera aitkenii

Workers collected by Fred Rickson at Calicut, India were visiting extrafloral nectary glands of cashew trees (Anacardium occidentale). (Ward 2001)

Identification
Ward (2001) - Tetraponera aitkenii can be identified by the combination of small size (worker HW <0.90, queen HW- 0.95), abundant pilosity on the mesosoma (MSC >20) and sides of head, and moderately dense pubescence on the gaster. Workers differ from those of the superficially similar Tetraponera polita by the larger eyes (REL >0.40), thinner petiole (PWI <0.58), and longer standing hairs. Workers of T. aitkenii might also be confused with those of Tetraponera nixa and the more setose forms of Tetraponera nitida, but these latter have shorter scapes (SI <0.56, SI3 <1.00), posteroventral teeth on the petiole, and dense punctate sculpture on the anterior quarter of the pronotum.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Malaysia. Oriental Region: Bangladesh, India, Thailand. Palaearctic Region: China.

Nomenclature

 *  aitkenii. Sima aitkenii Forel, 1902c: 245 (w.) INDIA. Wheeler, G.C. & Wheeler, J. 1956: 388 (l.). Combination in S. (Tetraponera): Emery, 1921f: 25; in Tetraponera: Chapman & Capco, 1951: 78. See also: Ward, 2001: 617.

Worker
Ward (2001) - HW 0.75-0.85, HL 0.87-1.05, LHT 0.62-0.68, CI 0.81-0.87, FCI 0.11-0.14, REL 0.41-0.44, REL2 0.48-0.55, SI 0.57--0.64, SI3 1.04-1.28, FI 0.42-0.48, PLI 0.58-0.64, PWI 0.49-0.55, PDI 0.99-1.05, LHT/HW 0.80-0.85, CSC 18-27, MSC 26-48.

Relatively small species (HW <0.90, LHT <0.70); anterior clypeal margin broadly convex, edentate; distance between frontal carinae approximately equal to, or slightly greater than, maximum scape width; eyes of modest size (see REL and REL2 values), eye length shorter than scape length; profemur moderately robust (FI 0.42-0.48); pronotum with sharply defined lateral margins; anterior half of mesopropodeal impression open and with irregular longitudinal rugulae, posterior half flanked by a pair of raised ridges (immediately mesad of the metanotal spiracles) that create a small, pit-like depression; propodeum about as high as wide (PDI - 1.00), the summit broadly rounded when seen in posterior view; in lateral profile, dorsal face rounding gradually into the declivitous face; petiole as sketched, about twice as long as wide, lacking posteroventral teeth; metabasitarsal sulcus well developed, adjacent to a prominent darkened ridge, occupying about half the length of the metabasitarsus. Integument largely smooth and shiny, with scattered punctures and fine, irregular lineations; largest punctures on head about 0.010-0.015 mm in diameter, usually separated by several to many diameters, but accompanied by, and grading into, more numerous, very fine punctures; lower malar area with coarser punctures and weak, irregular longitudinal rugulae. Standing pilosity (slender, fine-tipped hairs) common on most body surfaces, including scapes, legs, venter of head, sides and upper surface of head, mesosoma dorsum, petiole, postpetiole and gaster; setae on head and mesosoma variable in length, mostly 0.08-0.20 mm long; shorter appressed pubescence occurring in moderate density on body; appressed hairs on abdominal tergite IV separated by about their lengths or less. Body black to brownish-black, appendages lighter (dark to medium brown).

Type Material
Ward (2001) - Syntype (unique?), worker, Kanara, India (Aitken).

Determination Clarifications
Ward (2001) - Wheeler and Wheeler's (1956) description of the larva of Tetraponera aitkeni is actually that of Tetraponera allaborans.