Technomyrmex elatior

Found on trees and nests in rotten parts of the trunk.

Identification
Bolton (2007) - Superficially similar to Technomyrmex albipes and Technomyrmex vitiensis but with a broader head that is much more extensively and deeply emarginate posteriorly, more like the shape of Technomyrmex modiglianii. The anterior clypeal margin has a small but distinct shallow semicircular notch and the eyes are farther removed from the outline of the sides of the head in full-face view. The metathoracic spiracle, usually on a small but prominent tubercle, projects more dorsally than in either albipes or vitiensis and is conspicuous in profile in most samples.

T. elatior is probably most closely related to, and has also been confused with modiglianii because of its head shape and median clypeal notch, but elatior always lacks setae on the dorsum of the head behind the level of the posterior margin of the eye and has the main setae on the first gastral tergite distinctly much shorter than the maximum diameter of the eye.

This widely distributed taxon is size-variable as thus defined and may contain more than one species. In particular specimens from Sarawak tend to be larger (the largest - HL 0.84 - 0.88, HW 0.84 - 0.93), have the shortest scapes (SI 84 - 86) and have the eyes located more anteriorly (EPI 50 - 57) than the other populations. The last ratio is particularly striking as the other material in combination has EPI 63 - 73. However, because of shortage of examples and their otherwise similar morphology all are currently being retained as a single species.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Brunei Darussalam, Indonesia, Malaysia, Philippines, Singapore. Oriental Region: Cambodia, India, Nepal, Sri Lanka, Vietnam. Palaearctic Region: China, Italy.

Nomenclature

 *  elatior. Technomyrmex modiglianii r. elatior Forel, 1902d: 293 (w.) INDIA. Forel, 1908a: 3 (m.). Subspecies of modiglianii: Forel, 1905c: 23; Wheeler, W.M. 1921c: 541. Raised to species: Bingham, 1903: 302; Mukerjee, 1930: 155. Senior synonym of cordiformis: Bolton, 2007a: 79.
 * cordiformis. Technomyrmex albipes var. cordiformis Viehmeyer, 1916a: 143 (w.) SINGAPORE. Junior synonym of elatior: Bolton, 2007a: 79.

Worker
Bolton (2007) - TL 2.9 - 3.7, HL 0.65 - 0.88, HW 0.62 - 0.93, SL 0.59 - 0.78, PW 0.41 - 0.56, WL 0.78 - 1.00 (20 measured). Indices: CI 95 - 106, SI 84 - 98, OI 20 - 26, EPI 50 -73, DTI 112 - 128.

Frontal carina with 2 (rarely 3) setae. Dorsum of head behind level of eye entirely lacks setae. Anterior clypeal margin with a small but incised and sharply defined shallow semicircular median notch; inner margin of notch does not meet the anterior clypeal margin in an acute angle or tooth. Posterior margin of head in full-face view is broadly emarginate across its width, not merely with a median impression; depth and intensity of emargination increases with size, being most pronounced in the largest individuals. Sides of head convex and the outer margins of the eyes are set well in from the outline of the sides in full-face view. With mesosoma in profile the mesonotal outline is evenly curved, without a distinct step or angle in the outline that defines conspicuous dorsal and declivitous faces. Propodeal dorsum short, in profile the straight-line length of the dorsum less than the depth of the declivity to the spiracle; dorsum and declivity meet in an angle. Number of setal pairs on mesosoma: pronotum 2 - 3; mesonotum usually 1, located quite close to the metathoracic spiracle, but rarely a more anterior pair may also be present; propodeal dorsum 0; lateral margins of propodeal declivity 2 - 3. Gastral tergites 1 - 4 each with numerous setae all over the sclerites; these setae relatively short, the longest on the first gastral tergite only about 0.50 x the maximum diameter of the eye. Head, mesosoma, petiole and gaster dark brown to black; leg segments approximately the same colour as head and body except for the tarsi, which are yellowish.

Type Material
Bolton (2007) - Syntype workers, India: Assam, LXXIX/I6 (Long) [examined].