Aenictus longinodus

The type series, two colonies from Ton Nga Chang Wildlife Sanctuary, and a colony from Khao Luang National Park were collected in lowland rainforests. A colony was collected from an open area in the day, while a colony, just coming out of soil, was from a disturbed forest near a concrete road in the night. Thus, this species inhabits both primary and disturbed forests and is active in the day and night. (Jaitrong & Yamane 2012)

Identification
This species is most similar to Aenictus javanus (see A. javanus for details).

A member of the javanus species group.

Key to Aenictus species groups

Distribution
Malay Peninsula (S. Thailand)

Distribution based on Regional Taxon Lists
Oriental Region: Thailand.

Nomenclature

 *  longinodus. Aenictus longinodus Jaitrong & Yamane, 2012: 59, figs. 4, 7B (w.) THAILAND.

Worker
Holotype: TL 2.55 mm; HL 0.55 mm; HW 0.53 mm; SL 0.33 mm; ML 0.80 mm; PL 0.25 mm; CI 95; SI 62.

Larger workers (paratypes, n = 8): TL 2.45-2.60 mm; HL 0.55-0.58 mm; HW 0.53- 0.55 mm; SL 0.33-0.35 mm; ML 0.80-0.88 mm; PL 0.25 mm; CI 95-96; SI 61-64. Smaller workers (paratypes, n = 4): TL 1.90-2.00 mm; HL 0.45-0.53 mm; HW 0.40-0.43 mm; SL 0.22-0.28 mm; ML 0.63-0.73 mm; PL 0.18-0.19 mm; CI 85-89; SI 56-61.

Head in full-face view slightly longer than broad, with sides convex and posterior margin almost straight; seen in profile occipital corner of head rounded. Antennal scape reaching midlength of head; antennal segment II longer and narrower than each of III-VI; terminal segment about 2 times as long as broad. Anterior margin of clypeus bearing 7 denticles. Masticatory margin of mandible with 3 acute teeth including a large apical tooth; basal margin lacking denticles. Promesonotum seen in profile almost flat or weakly convex dorsally and sloping gradually to propodeal junction; in profile propodeum slightly lower than promesonotum and almost flat dorsally; propodeal junction angulate, right-angled; declivity of propodeum shallowly concave, encircled by a thin rim. Petiole longer than high, its dorsal outline convex; subpetiolar process well developed, subrectangular, its ventral margin almost straight or weakly convex and slightly longer than posterior margin; postpetiole seen in profile subrectangular and slightly shorter than petiole.

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

Head and mesosoma dorsally with relatively sparse standing hairs mixed with sparse short hairs over the surface; longest pronotal hairs 0.13-0.15 mm long. Head, mesosoma, petiole and postpetiole reddish brown; gaster yellowish brown and paler than the other parts of body; propodeum darkest.

Type Material
Holotype worker from S. Thailand, Trang Prov., Khao Chong Botanical Garden, evergreen forest, 8.XI.2003, W. Jaitrong, THNHM-I03–942 (= TH03-WJT-713, ). Thirty-seven paratype workers, same data as holotype.

Etymology
The specific name refers to the long petiole.