Aenictus rotundicollis Jaitrong & Yamane, 2011, sp. nov.
Creators: name: Jaitrong, Weeyawat
name: Yamane, Seiki
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Aenictus
Aenictus rotundicollis

description: Aenictus rotundicollis sp. nov.
(Figs. 41–43)
Types. Holotype worker from Malaysia, Sarawak, Niah N.P., 28 I 1993, Sk. Yamane leg (FRCS). Twenty-one paratype workers, same data as holotype (BMNH, MCZC, SKYC, THNHM, UMS).
Measurements. Holotype and paratypes (n = 10): TL 4.15–4.25 mm; HL 0.85–0.90 mm; HW 0.80–0.85 mm; SL 0.68–0.73 mm; ML 1.30–1.35 mm; PL 0.28–0.30 mm, CI 94–95; SI 84–85.
Description of worker (holotype and paratypes). Head in full-face view rounded, almost as long as broad, with sides strongly convex and posterior margin almost straight or weakly convex; occipital carina complete. Antennal scape relatively short, not reaching posterolateral corner of head; antennal segments II–X each longer than broad; II almost as long as each of III–V; terminal segment (X) almost as long as VII+VIII+IX. Frontal carina short, extending slightly beyond posterior margin of torulus. Anterior margin of clypeus slightly convex, bearing 5–6 denticles. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth, 4 denticles, and a small basal tooth; basal margin bearing 2–3 small teeth. Mesosoma relatively stout; promesonotum in profile strongly convex and forming a dome, mesonotum sloping to metanotal groove; propodeum distinctly lower than promesonotum, with its dorsal outline almost straight; propodeal junction roundly angulate; declivity in profile vertical and almost straight, without any trace of dorsal and lateral carinae. Petiole relatively short, almost as long as high and slightly shorter than postpetiole; subpetiolar process well developed and subtriangular, its apex directed downward and backward; postpetiole almost as long as high, dorsum of node more rounded than in petiole.
Entire head smooth and shiny. Sculpture of mandible very fine, not typically striate as seen in other species; the sculpture also covering outer zone, and only apical and masticatory zones smooth. Antennal scape superficially reticulate and shiny. Pronotum smooth and shiny, with its anteriormost portion punctate; mesonotum longitudinally rugulose; mesopleuron, metapleuron and propodeum entirely punctate. Petiole densely punctate; postpetiole shagreened with smooth and shiny interspaces.
Head with a pair of standing hairs on vertex; promesonotum with 2–3 standing hairs. Entire body dark reddishbrown. Typhlatta spot well developed, located anterior to occipital corner.
Non-type material examined. MALAYSIA: Sabah, Poring, Kinabalu N.P., 800 m alt., 17 III 1995, T. Kikuta leg. (SKYC, THNHM). BRUNEI: Tasek Merinbun, 13 II 1999, K. Eguchi leg., Eg99-BOR-079 (SKYC, THNHM).
Etymology. The specific name is a noun describing the roundly raised promesonotum.
Distribution. Borneo (Sabah, Sarawak, and Brunei) (Fig. 66).
Bionomics. A. rotundicollis is very probably sympatric with the closely related A. sonchaengi and inhabits lowland rainforests. So far it is known only from Borneo.
Remarks. This species is very similar to A. sonchaengi in having only 2 long standing hairs on the vertex of the head and the dorsally strongly convex promesonotum which forms a high dome. See under A. sonchaengi and also ‘Remarks’ for A. breviceps and A. laeviceps.
description: Published as part of Jaitrong, Weeyawat & Yamane, Seiki, 2011, Synopsis of Aenictus species groups and revision of the A. curra x and A. laeviceps groups in the eastern Oriental, Indo-Australian, and Australasian regions (Hymenoptera: Formicidae: Aenictinae), pp. 1-46 in Zootaxa 3128 on pages 41-42, DOI: 10.5281/zenodo.207090