Aenictus javanus Emery, 1896

Jaitrong, Weeyawat & Yamane, Seiki, 2012, Review of the Southeast Asian species of the Aenictus javanus and Aenictus philippinensis species groups (Hymenoptera, Formicidae, Aenictinae), ZooKeys 193, pp. 49-78 : 56-58

Aenictus javanus Emery, 1896 Figs 37B

Aenictus javanus Emery 1896: 245; Forel 1909: 222; Wilson 1964: 467 figs 36; Bolton 1995: 59.

Types.

Two syntype males from Java, Buitenzorg [Bogor] (MCSN, examined).

Measurements.

Non-type workersfrom 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.

Description of worker

(non-type workers from the type locality). 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. Peti ole 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 redish brown, mesosoma, petiole and postpetiole reddish brown; gaster yellowish brown. Typhlatta spot absent.

Non-type material examined.

MALAYSIA: Borneo, Sabah, Sandakan, Sepilok, Water Hole Trail, 30.V.2005, Alveron leg., A46 (SKYC); Borneo, Sabah, Sepilok forest, 27.I.1997, K. Eguchi leg., Eg97-BOR-506; Borneo, Sarawak, Lambir Hills N.P., 8 ha Plot, 11.VII.2004, H.O. Tanaka leg., TY04-801 (SKYC, THNHM). BRUNEI: Temburong, Kuala Belalong, Field Studies Centre, 19.II.1999, K. Eguchi leg., Eg97-BOR-225 (SKYC, THNHM). INDONESIA: W. Java, Bogor, Kebun Raya, 9.XII.1995, F. Ito leg., FI95-536 (SKYC, THNHM); same loc., 25.II.1997, F. Ito leg., FI97-06 (SKYC, THNHM).

Six workers from Java (2 pins, three on each pin, labeled as typus) identified as Aenictus javanus by Auguste-Henri Forel (MHNG) were examined. This series should be the same as that cited in Forel (1909). These workers are not the types.

Distribution.

Borneo (Sabah, Sarawak, and Brunei) and Java (Bogor) (Fig. 7B).

Bionomics.

All colonies of this species were collected from lowland rainforests.

Remarks.

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 Aenictus longinodus than the others in having the long petiole. Aenictus javanus can be separated from Aenictus longinodus as follows: occipital margin of head in profile angulated, while rounded in Aenictus longinodus ; the lateral face of the pronotum that are reticulate but shiny (almost smooth in Aenictus longinodus ).