Aenictus longinodus Jaitrong & Yamane

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 : 58-59

Aenictus longinodus Jaitrong & Yamane sp. n. Figs 47B

Types.

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

Measurements.

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.

Description of worker

(holotype and paratypes). 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.

Etymology.

The specific name refers to the long petiole.

Non-type material examined.

THAILAND: S. Thailand, Nakhon Si Thammarat Prov., Nuppitam Dist., Khao Luang N.P., Krung Ching waterfall, rainforest, 20.V.2003, W. Jaitrong leg., THTHM-I03-3779 (= TH03-WJT330, THNHM); Trang Prov., Palian Dist., Ban Suso, Open area, 31.X.2011, W. Jaitrong leg., TH11-WJT-183 (SKYC, THNHM); Songkhla Prov., Ton Nga Chang W.S., 5.II.1998, N. Noon-anant leg., N98-3 (SKYC, THNHM); same loc., 29.X.1997, N. Noon-anant leg., N97-1 (SKYC, THNHM); Songkhla Prov., Hat Yai, Songkhlanakarin Campus, PSU forest, 21.X.2011, Sk. Yamane leg., TH11-SKY-166 (SKYC, THNHM).

Distribution.

Malay Peninsula (S. Thailand) (Fig. 7B).

Bionomics.

The type series, two colonies from Ton Nga Chang Wildlife Sanctuary (N98-3 and N97-1), and a colony from Khao Luang National Park (TH03-WJT330) were collected in lowland rainforests. A colony (TH11-WJT-183) was collected from an open area in the day, while a colony (TH11-SKY-166), 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.

Remarks.

This species is most similar to Aenictus javanus . See under Aenictus javanus for details.