Aenictus punctatus 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 : 68-70

Aenictus punctatus Jaitrong & Yamane sp. n. Figs 1012

Types.

Holotype from Brunei, Tasek Merimbun, 13.II.1999, K. Eguchi leg. Eg99-BOR-078 (SKYC). Nineteen paratype workers, same data as holotype (BMNH, MCZC, MHNG, SKYC, THNHM).

Measurements.

Holotype: TL 4.50 mm; HL 0.98 mm; HW 0.85 mm; SL 0.70 mm; ML 1.38 mm; PL 0.33 mm; CI 87; SI 82.

Paratypes (n = 9): TL 4.30-4.40 mm; HL 0.95-0.98 mm; HW 0.83-0.85 mm; SL 0.68-0.73 mm; ML 1.33-1.35 mm; PL 0.28-0.30 mm; CI 87; SI 82-85.

Description of worker

(holotype and paratypes). Head in full-face view elliptical, clearly longer than broad, with sides convex and posterior margin almost straight or weakly convex; occipital margin forming a distinct carina; seen in profile occipital corner of head rounded. Antennal scape relatively long, extending 3/4 of head length; antennal segment II almost as long as each of III-VI; terminal segment slightly shorter than VII+VIII+IX. Frontal carinae short fused at the level of antennal base to form a single carina and slightly extending beyond 1/4 of head length, poorly developed in posterior half. Parafrontal ridge short, extending less than 1/3 of head length, 0.30-0.33 mm long. Masticatory margin of mandible with a series of 6-7 denticles of same size; basal margin of mandible lacking denticles. Mesosoma in profile with promesonotum convex dorsally and sloping gradually to metanotal groove; metanotal groove indistinct compared with those of the other members of the group; mesonotum demarcated from mesopleuron by a conspicuous ridge. Propodeum almost flat or weakly convex dorsally; declivity of propodeum shallowly concave, encircled with a developed rim; seen in profile dorsal portion of the rim protruding posteriad. Petiole subsessile, slightly longer than high, its dorsal outline elevated posteriorlly; subpetiolar process very low, its ventral outline weakly convex; postpetiole longer and larger than petiole and slightly longer than high, with its dorsal outline convex. Legs relatively long with apical halves of femora and tibiae somewhat swollen.

Head entirely finely punctate; mandible very finely striate except along masticatory margin; antennal scape finely punctate. Pronotum entirely punctate; mesopleuron, metapleuron and lateral face of propodeum punctate; dorsal face of propodeum finely punctate. Petiole entirely punctate; postpetiole punctate with weakly sculptured and shiny anterior slope of node. Basal half of femora densely punctate but apical half superficially macroreticulate and shiny; tibiae macroreticulate and shiny.

Head and mesosoma dorsally with sparse standing hairs mixed with very short hairs; longest pronotal hair 0.25-0.28 mm long. Entire body dark reddish brown. Typhlatta spots absent.

Etymology.

The species epithet “punctatus” is a Latin word meaning punctate. This refers to the finely punctate head of this species, while the head is reticulate or smooth and shiny in the other species of the Aenictus philippinensis group.

Non-type materials examined.

Malaysia: Borneo, Sabah, Sepilok Forest, 27.VIII.1995, Sk. Yamane leg. (SKYC, THNHM); Borneo, Sabah, Danum Valley, 4.XII.1996, K. Eguchi leg., Eg96-BOR-155 (SKYC); Borneo, Sabah, Tawau, Gunong Rara 9.XI.1996, K. Eguchi leg., Eg96-BOR-323 (SKYC, THNHM); Borneo, Sarawak, Sg. Segerugok, Song, 22.IX.1993, A. Rahman leg. (SKYC); Borneo, Sarawak, Semengoh N.P., 18.IV.1993, Sk. Yamane leg. (SKYC, THNHM); Borneo, Sarawak, Miri, Lambir N.P., Head Quarter, 17.VIII.1995, H. Okido leg. (SKYC, THNHM); same loc., 8 ha plot, 30.VI.2004, Sk. Yamane leg., SR04-SKY-38 (SKYC, THNHM). BRUNEI: Tasek Merimbun, 17.II.1999, A. Tuah leg., Eg99-BOR-130 (SKYC, THNHM). INDONESIA: E. Kalimantan, Kutai N.P., Sangkimah, 8.IX.1993, Sk. Yamane leg. (SKYC, THNHM); Java, Ujung Kulou, Cibon, 15.III.1997, F. Ito leg., FI97-182 (SKYC, THNHM).

Distribution.

Borneo (Sabah, Sarawak, Brunei, and E. Kalimantan) and Java (Fig. 12).

Bionomics.

All the members of the Aenictus philippinensis group are probably restricted to the Philippines except for Aenictus punctatus that is distributed on Borneo and Java. All of the materials of this species examined were collected from lowland rainforests. A colony from Sarawak was collected from rotten wood in September 1993. A colony from Lambir National Park (SR04-SKY-38) was collected at night.

Remarks.

This species is closely related to Aenictus philippinensis . See under Aenictus philippinensis for details.