Aenictus javanus

All colonies of this species were collected from lowland rainforests.

Identification
Jaitrong & Yamane (2012) - A member of the javanus species group. This species is closely related to Aenictus doydeei, Aenictus longinodus, and Aenictus nishimurai in terms of body size and coloration. Among these species is more closely related to A. longinodus than the others in having the long petiole. A. javanus can be separated from A. longinodus as follows: occipital margin of head in profile angulated, while rounded in A. longinodus; the lateral face of the pronotum that are reticulate but shiny (almost smooth in A. longinodus).

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Brunei Darussalam, Indonesia, Malaysia. Oriental Region: Thailand, Vietnam. Palaearctic Region: China.

Castes
Known only from the worker caste.

Nomenclature

 * . Aenictus javanus Emery, 1896f: 245, figs. (m.) INDONESIA (Java) (attributed to Ritsema).
 * Forel, 1909d: 222 (w.).
 * Status as species: Forel, 1909d: 222; Emery, 1910b: 30; Forel, 1911b: 194; Chapman & Capco, 1951: 16; Wilson, 1964a: 467; Bolton, 1995b: 59; Jaitrong & Nabhitabhata, 2005: 12; Pfeiffer, et al. 2011: 32; Guénard & Dunn, 2012: 23; Jaitrong & Yamane, 2012: 57 (redescription).

Worker
Wilson (1964) - HW 0.50 mm, HL 0.55 mm, SL 0.36 mm. Antenna 10-segmented. Mandible narrow, 4-toothed. Clypeal structure as in ceylonicus (q. v.). Parafrontal ridge absent. Occiput feebly convex, lacking a collar. Basal face of propodeum seen from side straight; propodeal junction forming an almost exact right angle. Subpetiolar process an acute tooth which curves posteriorly. Pilosity abundant; length of longest pronotal hairs 0.25 mm.

Head shining. Pronotum mostly shining. Remainder of mesosoma weakly microreticulate and subopaque; but, unlike the condition in ceylonicus, rugae are completely absent. Petiolar dorsum feebly microreticulate and feebly shining; remainder of petiolar more densely reticulate and subopaque to opaque. Postpetiole mostly shining. Color as in ceylonicus.

Jaitrong & Yamane (2012) - Non-type workers from the type locality (n = 8): TL 2.35-2.60 mm; HL 0.55-0.58 mm; HW 0.50-0.53 mm; SL 0.35 mm; ML 0.83-0.88 mm; PL 0.23-0.25 mm; CI 91; SI 67-70.

Head in full-face view slightly longer than broad, subrectangular, with sides convex and posterior margin almost straight or feebly concave; seen in profile occipital corner of head angulated. Antennal scape reaching midlength of head; antennal segment II almost as long as each of III-V; terminal segment longer than VII+VIII+IX and 2.2 times as long as broad. Anterior margin of clypeus bearing 6-7 denticles. Masticatory margin of mandible with 3 acute teeth including a large apical tooth; basal margin lacking denticles. Promesonotum in profile weakly convex dorsally or almost flat and sloping gradually to propodeal junction; in profile propodeum almost flat dorsally; suture between mesopleuron and metapleuron almost absent; propodeal junction angulate, right-angled; declivity of propodeum shallowly concave, encircled by a thin rim. Petiole distinctly longer than high, its dorsal outline slightly elevated posteriorly; subpetiolar process well developed, subrectangular, its ventral border almost straight or feebly concave and as long as posterior border; postpetiole almost as long as, its dorsal outline slightly convex.

Head including antennal scape smooth and shiny; mandible striate along basal margin and smooth in apical and peripheral parts. Dorsal surface of pronotum smooth and shiny, lateral face of pronotum superficially reticulate but shiny; anteriormost part of pronotum microreticulate; mesothorax, metapleuron and propodeum microreticulate. Petiole entirely microreticulate. Postpetiole microreticulate except for a small area on dorsal surface smooth and shiny.

Head and mesosoma dorsally with relatively sparse standing hairs mixed with sparse short hairs; longest pronotal hairs 0.15–0.18 mm long. Head yellowish brown to reddish brown, mesosoma, petiole and postpetiole reddish brown; gaster yellowish brown. Typhlatta spot absent.

Type Material
Jaitrong & Yamane (2012) - Two syntype males from Java, Buitenzorg [Bogor] (, examined).

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.
 * Borowiec M. L. 2016. Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae). ZooKeys 608: 1–280.
 * 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
 * Chapman, J.W. and S.R. Capco. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monographs of the Institute of Science and Technology (Manila) 1: 1- 327
 * Emery C. 1910. Hymenoptera. Fam. Formicidae. Subfam. Dorylinae. Genera Insectorum 102: 1-34.
 * Emery, C. "Formicides recoltes a Buitenzorg (Java), par M. Massart." Annales de la Société Entomologique de Belgique 40 (1896): 245-249.
 * Forel A. 1909. Ameisen aus Java und Krakatau beobachtet und gesammelt von Herrn Edward Jacobson. Notes Leyden Mus. 31: 221-232.
 * Forel A. 1911. Ameisen aus Java beobachtet und gesammelt von Herrn Edward Jacobson. II. Theil. Notes Leyden Mus. 33: 193-218.
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Herwina H., and K. Nakamura. 2007. Ant species diversity study using pitfall traps in a small yard in Bogor Botanic garden, West Java, Indonesia. Treubia 35: 99-116.
 * Ito, F.; Yamane, S.; Eguchi, K.; Noerdjito, W. A.; Kahono, S.; Tsuji, K.; Ohkawara, K.; Yamauchi, K.; Nishida, T.; Nakamura, K. 2001. Ant species diversity in the Bogor Botanic Garden, West Java, Indonesia, with descriptions of two new species of the genus Leptanilla (Hymenoptera, Formicidae). Tropics 10:379-404.
 * Jaitrong W., and S. Yamane. 2012. Review of the Southeast Asian species of the Aenictus javanus and Aenictus philippinensis species groups (Hymenoptera, Formicidae, Aenictinae). ZooKeys 193: 49-78.
 * Jaitrong W.; Nabhitabhata, J. 2005. A list of known ant species of Thailand. The Thailand Natural History Museum Journal 1(1): 9-54.
 * Jaitrong, W., and S. Yamane. "Review of the Southeast Asian species of the Aenictus javanus and Aenictus philippinensis species groups (Hymenoptera, Formicidae, Aenictinae)." ZooKeys 193 (2012): 49-78.
 * 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
 * Wang C. and Wu J. 1992. Ants of the Jianfengling forest region in Hainan Province (Hymenoptera: Formicidae). Scientia Silvae Sinicae 28: 561-564.
 * Wilson E. O. 1964. The true army ants of the Indo-Australian area (Hymenoptera: Formicidae: Dorylinae). Pacific Insects 6: 427-483.