Aenictus jawadwipa

The type series of this species was collected from highland (ca. 1,300m alt., W. Java) by a stream in a primary forest. The non-type colonies from Borneo were all collected from lowland primary forests (200-700m alt.). This species was active both day and night.

Identification
A member of the ceylonicus group. Aenictus jawadwipa is most similar in general appearance to Aenictus eguchii. (Jaitrong and Yamane 2013)

Key to Aenictus species groups / Key to southeastern Asian Aenictus ceylonicus group species

Distribution
Borneo (Sabah and Sarawak) and W. Java

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

Nomenclature

 *  jawadwipa. Aenictus jawadwipa Jaitrong & Wiwatwitaya, 2013: 193, figs. 23A-C (w.) INDONESIA.

Worker
(Holotype and paratype workers, n = 10): TL 2.40–2.90 mm; HL 0.53–0.58 mm; HW 0.48–0.53 mm; SL 0.40–0.45 mm; ML 0.78–0.88 mm; PL 0.20–0.23 mm; CI 90–91; SI 84–86.

Head in full-face view slightly longer than broad, sides convex, posterior margin weakly convex; occipital margin bearing a carina. Antennal scape relatively short, reaching 2/3 of head length. Frontal carina relatively long, slightly extending beyond the level of posterior margin of torulus. Parafrontal ridge feeble and incomplete. Anterior clypeal margin feebly concave. Masticatory margin of mandible with large acute apical tooth followed by a medium-sized subapical tooth, and 4 denticles; basal margin almost straight. Maximum width of gap between anterior clypeal margin and mandibles about 1.9 times as broad as maximum width of mandible. Promesonotum strongly convex dorsally and sloping gradually to metanotal groove; mesopleuron relatively long, not clearly demarcated from metapleuron; metapleural gland bulla relatively small, its maximum diameter about 1.6 times as long as distance between propodeal spiracle and metapleural gland bulla. Propodeum in profile relatively long, with straight dorsal outline; propodeal junction acutely angulated, overhanging the declivitous face of propodeum; the declivity widely and shallowly concave, encircled with a distinct rim. Petiole almost as long as high, seen in profile its node short and dorsal outline convex; subpetiolar process developed, with anteroventral and posteroventral corners angulated, margin connecting anterior and posterior corners strongly concave. Postpetiole slightly smaller than petiole, with its dorsal outline convex.

Head and gaster entirely smooth and shiny. Mandible very finely striate. Basal portion of antennal scape microreticulate, 2/3 apical smooth and shiny. Pronotum entirely smooth and shiny except for anteriormost portion densely punctate; mesopleuron, metapleuron, propodeum, and petiole reticulate; in addition mesopleuron and metapleuron with 3-4 longitudinal or irregular rugae; anterior, lateral and posterior faces of postpetiole reticulate, but its dorsum smooth and shiny.

Head and mesosoma dorsally with relatively dense standing hairs mixed with decumbent hairs; longest pronotal hair 0.25–0.28 mm long. Head, petiole, gaster, and legs yellowish brown; mesosoma reddish brown.

Type Material
Holotype. INDONESIA: Worker from W. Java, Cibodas Botanical Garden, 29.XI.2009, leg. W. Jaitrong, WJT09-ID16 (MZB). Paratypes. Forty-three workers, same data as holotype (BMHN, MCZC, MZB, SKYC, THNHM).

Etymology
The specific name is after the type locality, Java Island (in Sanscrit).