Leptogenys aspera

Identification
In full-face view, head longer than wide (CI: 72–77). In full-face view, eye situated anterior to mid-length of head, breaking lateral outline of head. Mandible with basal angle; basal margin with three teeth; masticatory margin with three teeth including apical tooth. Anterior edge of torulus anterior to transverse line extending across mandible bases. Clypeus projecting apically into trapezoidal lobe, with longitudinal median carina; apex truncate; median lobe short (CLI: 15–17). Hypostomal tooth absent. Petiole in profile higher than long, in dorsal view longer than wide; in profile, petiolar node rectangular, highest posteriorly; anterior and posterior margins inclined anteriad. Subpetiolar process consisting of fan-shaped anterior lobe and thin posterior extension.

This species is easily recognized by the remarkable structure of the mandible with seven teeth (three short teeth on basal margin, basal angle, two distinct teeth on masticatory margin and an acute apical tooth) (Fig. 4A).

Distribution
Arimoto (2017) did not find evidence of this species occurring in Sulawesi, Indonesia. The record from Sulawesi based on the larva described by Wheeler & Wheeler (1976) is most likely a misidentification.

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

Castes
Queen and male unknown (Arimoto, 2017).

Nomenclature

 *  aspera. Lobopelta aspera André, 1889: 222 (w.) VIETNAM. Wheeler, G.C. & Wheeler, J. 1976a: 52 (l.). Combination in Leptogenys: Forel, 1900d: 310. See also: Bingham, 1903: 60.

Taxonomic Notes
Arimoto (2017) examined specimens from the four areas: central Vietnam, central Laos, east Thailand, and south Thailand. Measurements of body parts in these specimens showed no noticeable variation between the populations. However, variation was found in the shape of the propodeum. In the specimens from central Laos the propodeal dorsum and declivity form a continuous curve, while in those from Vietnam and Thailand the dorsum is separated from the declivity by a blunt angle. The two ‘forms’, here considered to represent geographical variation, are allopatric in range. Morphological variation among sympatric individuals was observed in the proportion of the anterior lobe of the subpetiolar process (Fig. 4C, D), body surface sculpture, and coloration.

References based on Global Ant Biodiversity Informatics

 * Arimoto K. 2017. Redescription of Leptogenys aspera (André, 1889) (Hymenoptera, Formicidae, Ponerinae) from Southeast Asia. Japanese Journal of Systematic Entomology 23 (1): 15–19.
 * Chapman, J. W. & Capco, S. R., 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monographs of the Institute of Science and Technology, 1: 1–327.
 * Forel, A., 1900. Les formicides de l'Empire des Indes et de Ceylan. Part VII. Journal of the Bombay Natural History Society, 13: 303–332. http://10.5281/ZENODO.14396
 * Ogata K. 2005. Asian ant inventory and international networks. Report on Insect inventory Project in Tropic Asia TAIIV: 145-170.
 * 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
 * Xu Z. H., and Q. J. He. 2015. Taxonomic review of the ponerine ant genus Leptogenys ROGER, 1861 (Hymenoptera: Formicidae) with a key to the Oriental species. Myrmecological News 21: 137-161.