Aenictus cornutus

All colonies of this species have been collected from lowland rainforests. Rościszewski and Maschwitz (1994) reported that in the Pasoh Forest Reserve, Malaysia, Aenictus cornutus foraged on the ground and feed on ants of the genera Polyrhachis and Technomyrmex. (Jaitrong and Yamane 2011)

Identification
This species is easily distinguished from the other members of the currax group as follows: pronotum armed with large bilateral horn-like protuberances; antennal scape, legs and postpetiole distinctly punctate.

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

Castes
Known only from the worker caste.

Nomenclature

 * . Aenictus cornutus Forel, 1900b: 75 (w.) BORNEO (East Malaysia: Sarawak).
 * Type-material: lectotype worker (by designation of Jaitrong & Yamane, 2011: 11), 3 paralectotype workers.
 * [Note: 1 original syntype worker also in NHMB.]
 * Type-locality: lectotype Malaysia: Borneo, Sarawak (Haviland); paralectotypes with same data.
 * Type-depository: MHNG.
 * Status as species: Emery, 1910b: 29; Wheeler, W.M. 1919e: 62; Chapman & Capco, 1951: 15; Wilson, 1964a: 457; Terayama & Yamane, 1989: 597; Bolton, 1995b: 59; Jaitrong & Yamane, 2011: 11 (redescription); Pfeiffer, et al. 2011: 32.
 * Distribution: Indonesia (Sumatra), Malaysia (Peninsula, Sabah, Sarawak).

Worker
Jaitrong and Yamane (2011) - Measurements. lectotype and paralectotypes (n = 4): TL 4.00–4.45 mm; HL 0.83–0.88 mm; HW 0.73–0.78 mm; SL 0.80–0.88 mm; ML 1.48–1.55 mm; PL 0.35–0.38 mm; CI 86–89; SI 107–114.

(lectotype and paralectotypes). Head in full-face view clearly longer than broad, with sides slightly convex and posterior margin sinuate; occipital margin bearing a narrow collar. Antenna relatively thick; scape not reaching posterolateral corner of head; antennal segments II–VI slightly longer than broad, of approximately same length; VII–IX thicker and slightly longer; X slightly longer than VIII+IX. Frontal carina short, slightly extending beyond the level of posterior margin of torulus and well developed anteriorlly. Parafrontal ridge short and bluntly pointed at apex. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth and 5–6 denticles; basal margin of mandible lacking denticles. Mesosoma slender; pronotum anteriorly armed with large bilateral horn-like protuberances, a unique character within the species group. Propodeum in profile with weakly convex dorsal outline; propodeal junction angular; declivity of propodeum shallowly concave, and encircled with a thin rim. Petiole distinctly longer than high, with its dorsal outline elevated posteriorlly; subpetiolar process low, with its anteroventral corner angulate, and ventral margin almost straight, sometimes with lamellate lower portion. Postpetiole distinctly longer than high, with its dorsal outline convex.

Head entirely smooth and shiny. Mandible very finely striate except for masticatory and outer zones. Antennal scape punctate. Pronotum smooth and shiny except for the anteriormost portion and pronotal horns which are punctate; mesothorax, metapleuron, and propodeum with dense punctures and bearing several longitudinal rugulae.

Petiole and postpetiole densely punctate as are metathorax and propodeum. Legs densely punctate. Head and mesosoma dorsally with relatively sparse long standing hairs mixed with dense short hairs; longest pronotal hair 0.35 mm long. Entire body dark reddish-brown. Typhlatta spot located at the occipital corner.

Type Material
Jaitrong and Yamane (2011) - Four syntype workers (two on each of the two pins) from Borneo, Sarawak (, examined). One worker among them (bottom on a pin) is selected as the lectotype, the others as paralectotypes.

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1977. Katalog der Typen von Formicidae (Hymenoptera) der Sammlung des Naturhistorischen Museums Basel (2. Teil). Mitt. Entomol. Ges. Basel (n.s.) 27: 61-102.
 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Emery C. 1910. Hymenoptera. Fam. Formicidae. Subfam. Dorylinae. Genera Insectorum 102: 1-34.
 * Forel A. 1900. Ponerinae et Dorylinae d'Australie récoltés par MM. Turner, Froggatt, Nugent, Chase, Rothney, J.-J. Walker, etc. Annales de la Société Entomologique de Belgique 44: 54-77.
 * Jaitrong W. 2015. A revision of the Thai species of the ant genus Aenictus Shuckard, 1840 (Hymenoptera: Formicidae: Dorylinae). The Thailand Natural History Museum Journal 9(1): 1-94.
 * Jaitrong W.; Yamane, S. 2011. Synopsis of Aenictus species groups and revision of the A. currax and A. laeviceps groups in the eastern Oriental, Indo-Australian, and Australasian regions (Hymenoptera: Formicidae: Aenictinae). Zootaxa 3128:1-46.
 * Malsch A. K. F., K. Rosciszewski, and U. Maschwitz. 2003. The ant species richness and diversity of a primary lowland rain forest, the Pasoh Forest reserve, West Malaysia. in T. Okuda, N. Manokaran, Y. Matsumoto, K. Niiyama, S. C. Thomas, and P. S. Ashton, eds. Pasoh: Ecology and Natural History of a Southeast Asin Lowland Tropical Rain Forest, pp 347-374.
 * Matsumoto T., T. Itioka, S. Yamane, and K. Momose. 2009. Traditional land use associated with swidden agriculture chnages encounter rates of the top predator, the army ant, in Southern Asian tropical rain forests. Biodivers. Conserv. 18: 3139-3151.
 * 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
 * Terayama M.; Yamane, S. 1989. The army ant genus Aenictus (Hymenoptera, Formicidae) from Sumatra, with descriptions of three new species. Japanese Journal of Entomology 57:597-603.
 * Wheeler W. M. 1919. The ants of Borneo. Bulletin of the Museum of Comparative Zoology 63:43-147.
 * Wilson E. O. 1964. The true army ants of the Indo-Australian area (Hymenoptera: Formicidae: Dorylinae). Pacific Insects 6: 427-483.