Technomyrmex impressus

A forest species that has been collected in litter samples.

Identification
Bolton (2007) - A member of the Technomyrmex bicolor group. Known only from Kinabalu, impressus is closest related to Technomyrmex gaudens. The relatively minor differences between them are noted under the latter name. T. impressus also resembles the Oriental Technomyrmex obscurior, but the latter lacks a notch in the dorsal outline of the propodeum and tends to have metathoracic spiracles that are more widely separated from the metanotal groove.

Among the admittedly sparse material examined the scape index decreases as overall size increases.

Distribution
Sabah, Malaysia.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia.

Nomenclature

 *  impressus. Technomyrmex impressus Bolton, 2007a: 86, fig. 59 (w.) BORNEO.

Worker
Holotype. TL 3.7, HL 0.91, HW 0.81, SL 1.08, PW 0.55, WL 1.30. lndices: CI 89, SI 133, OI 28, EPI 75, DTI 164.

Head behind c1ypeus, dorsum of mesosoma, declivity of propodeum and first gastral tergite all entirely lack setae. Gastral tergites 2 - 4 with long stout setae present that are slightly longer than the maximum diameter of the eye: second gastral tergite with 1 pair, third and fourth tergites each with 2 or 3 pairs. Anterior clypeal margin with a distinct median notch that is broader than long, the margins of which meet the lateral portions of the anterior margin through rounded curves, not sharp angles. Posterior margin of head concave, not deeply indented medially. With head in full-face view the outer margins of the eyes fail to touch the outline of the sides of the head; the latter convex, more strongly so in larger workers. Scape relatively long, SI 133 (SI range in all material examined 129 - 144). Clypeus finely and densely reticulate-punctulate everywhere. In dorsal view the metathoracic spiracles separated from the metanotal groove by distance of one spiracle diameter or slightly more. Mesosoma with DTI 164 (DTI range in all material examined 162 - 169). In profile the dorsal margin of the propodeum with a distinct indentation or notch at its midlength. Straight-line length of the propodeal dorsum more than twice the depth of the declivity to the spiracle. In profile the head, mesosoma, petiole and gaster all the same shade of dark brown to blackish brown, or very nearly so. Anterior coxa brown; middle and hind coxae off-white to yellow and strongly contrasting with the mesosoma and femora. All trochanters yellow. Femora and tibiae brown, slightly lighter than the mesosoma. Tarsi off-white to yellow, lighter than the femora and tibiae.

Other worker. TL 3.2 - 4.0, HL 0.84 - 0.94, HW 0.68 - 0.84, SL 0.98 - 1.08, PW 0.40 - 0.56, WL 1.14 - 1.38 (9 measured). Indices: CI 81 - 89, SI 129 - 144, OI 29 - 31, EPI 74 - 79, DTI 162 - 169. As holotype but second gastral tergite with 1 - 2 pairs of setae.

Type Material
Holotype worker (top specimen of 3 on pin), Malaysia: Sabah, Mt Kinabalu, Liwagu Trail, 1500 m., 21.v.19871 no. 43a (Lobi & Burckhardt). Paratypes. 2 workers (middle and bottom specimens on same pin), with same data (BMNH).

References based on Global Ant Biodiversity Informatics

 * Bolton B. 2007. Taxonomy of the dolichoderine ant genus Technomyrmex Mayr (Hymenoptera: Formicidae) based on the worker caste. Contributions of the American Entomological Institute 35(1): 1-150.
 * Bolton, B. "Taxonomy of the dolichoderine ant genus Technomyrmex Mayr (Hymenoptera: Formicidae) based on the worker caste." Contributions of the American Entomological Institute 35, no. 1 (2007): 1-149.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58