Aenictus brevinodus, Jaitrong, Weeyawat & Yamane, Seiki, 2011

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), Zootaxa 3128, pp. 1-46 : 33

Aenictus brevinodus sp. nov.

( Figs. 46–48 )

Types. Holotype worker from Indonesia, S. Sulawasi, Laiya, Labbang, 24 I 2010, Sk. Yamane leg., CE10-SKY-15 (MZB). Fourty-five paratype workers, same data as holotype (AMK, BMNH, SKYC, THNHM).

Measurements. Holotype and paratypes (n = 7): TL 3.65–3.75 mm; HL 0.78–0.83 mm; HW 0.70–0.73 mm; SL 0.65–0.70 mm; ML 1.15–1.20 mm; PL 0.23–0.25 mm; CI 88–91; SI 93–97.

Description of worker (holotype and paratypes). Head in full-face view rather oval, slightly longer than broad, with sides distinctly convex and posterior margin almost straight or weakly convex; occipital carina weak but complete. Antennal scape relatively short, in full-face view 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, slightly extending beyond posterior margin of torulus; parafrontal ridge absent. Anterior margin of clypeus slightly convex, bearing 8 denticles. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth, 3–4 denticles, a medium-sized subbasal tooth and a smaller basal tooth (the latter two widely separated from each other); basal margin lacking denticles. 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 rather sharply to roundly angulate; declivity of propodeum seen in profile vertical, almost straight or feebly concave, irregularly sculptured, without a distinct rim separating the declivity from other parts. Petiole subsessile and rather short, its node slightly shorter than high; subpetiolar process hook-like, variable in size, with apex directed downward and backward; postpetiole distinctly larger than petiole.

Entire head including antennal scape smooth and shiny. Mandible very finely striate except along masticatory margin and near base. Pronotum entirely smooth and shiny except for anteriormost portion punctate; dorsa of both mesothorax and propodeum extensively smooth; small posterior portions of mesothorax and propodeum, and lower part of metapleuron irregularly punctate or rugulose. Petiole and postpetiole entirely smooth and shiny. Legs entirely smooth and shiny.

Vertex with a pair of long standing hairs and very sparse short hairs. Mesosoma dorsally with relatively sparse standing hairs mixed with very sparse short hairs over the surface; longest pronotal hair 0.20–0.23 mm long. Entire body dark reddish-brown. Typhlatta spot located anterior to occipital corner.

Non-type material examined. Indonesia: S. Sulawesi, Mt. Kaleakan (1,080–1,140 m alt.), Tana Traja, 17 X 1999, K. Ogata and K. Masaoka leg. ( SKYC, THNHM).

Etymology. The specific name means the short petiole.

Distribution. Sulawesi ( Fig. 64 ).

Bionomics. This species occurs in lowland and highland forests. We found workers of the type series raiding on low vegetation along a road.

Remarks. A. brevinodus is quite similar to A. hodgsoni . However, it has fewer standing hairs on the mesosomal dorsum (less than 10 hairs in A. brevinodus ; more than 20 in A. hodgsoni ); the petiolar node is clearly shorter than high (almost as long as high or slightly longer than high in A. hodgsoni ); and the legs are entirely smooth and shiny (femora extensively superficially reticulate and shiny, and tibiae very finely reticulate in the latter).

Figures

FIGURES 44 – 50. Workers of Aenictus laeviceps group. 44, 45, A. breviceps, lectotype; 46 – 48, A. brevinodus sp. nov., holotype; 49, 50, A. hodgsoni, lectotype. 44, 46, 49, Head in full-face view; 45, 47, 50, habitus in profile; 48, dorsal view of body.

FIGURES 63 – 66. Distribution of Aenictus laeviceps group. 63, A. alticola, A. binghami, and A. fulvus sp. nov., A. luzoni; 64, A. bodongjaya sp. nov., A. breviceps, A. brevinodus sp. nov., and A. montivagus sp. nov.; 65, A. hodgsoni, and A. laeviceps; 66, A. sonchaengi sp. nov., A. rotundicollis sp. nov., and A. siamensis sp. nov.