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).

Key to Aenictus species groups / Key to Aenictus javanus group species

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

Nomenclature

 *  javanus. Aenictus javanus Emery, 1896f: 245, attributed to Ritsema, fig. (m.) INDONESIA (Java). Forel, 1909d: 222 (w.). See also: Wilson, 1964a: 467; Jaitrong & Yamane, 2012: 57.

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).