Crematogaster sundalandensis, Hosoishi & Ogata, 2016

Hosoishi, Shingo & Ogata, Kazuo, 2016, Systematics and biogeography of the ant genus Crematogaster Lund subgenus Orthocrema Santschi in Asia (Hymenoptera: Formicidae), Zoological Journal of the Linnean Society 176 (3), pp. 547-606 : 600-601

CREMATOGASTER SUNDALANDENSIS SP. NOV.

( FIG. 121 )

Holotype worker. Parapat (900 m alt.), Danau Toba, N. Sumatra, INDONESIA, 19.viii.2002 ( SU02-SKY-73 ) (Sk. Yamane) ( MBBJ).

Paratypes. Seven workers, same data as hotlotype ( BMNH, CASC, KUEC, MHNG, SKYC, THNHM) .

Worker measurements (n = 8): HW 0.44–0.53; HL 0.47– 0.55; CI 92–100; SL 0.42–0.49; SI 92–96; EL 0.12– 0.14; PW 0.29–0.35; WL 0.56–0.64; PSL 0.08–0.11; PtL 0.17–0.21; PtW 0.15–0.16; PtH 0.12–0.15; PpL 0.11– 0.13; PpW 0.16–0.19; PtHI 70–78; PtWI 80–88; PpWI 133–146; WI 106–107.

General description of worker: Workers monomorphic.

Head subquadratic in full-face view. Mandibles with four teeth arranged at an equal distance, apical and subapical teeth large, basal two teeth smaller. Anterior clypeal margin convex in medial portion. Compound eyes distinctly projecting beyond lateral margins of head in full-face view. Scapes reaching posterolateral corners of head.

Pronotal collar with weakly concave anterior margin in dorsal view, distinctly lower than pronotum in lateral view. Pronotal dorsum without distinct ridges laterally. Mesonotal dorsum with lateral ridges that irregularly extend posteriad to tips of propodeal spines. Pronotum and mesonotum in lateral view forming evenly arched, continuous dorsal outline. Metanotal groove in dorsal view transverse, almost straight in median portion, forming deep concavity that is laterally margined by lamellate ridges. Propodeal spiracles elliptical, situated at posterolateral corners of propodeum, touching to metapleural gland bullae. Propodeal spines developed, longer than diameter of propodeal spiracles, in dorsal view directed posteriad.

Petiole in dorsal view with subparallel sides and narrow anteriorly, longer than wide. Posterior portion of petiole without distinct process in lateral view. Subpetiolar process undeveloped. Postpetiole in lateral view with weakly convex dorsum, as high as petiole, in dorsal view as wide as petiole, weakly bilobed posteriorly but without longitudinal sulcus. Subpostpetiolar process undeveloped, but venter of postpetiole convex.

Integument essentially smooth and shining. Dorsal surface of head smooth and shining. Mandibles with feeble rugulae and smooth interspaces. Clypeus generally smooth and shining, but with one pair of longitudinal rugulae; rugulae not extending to posterior clypeal margin. Dorsal and lateral surfaces of pronotum smooth and shining; anterolateral shoulders of pronotum without rugulae. Mesopleura smooth and shining. Dorsal surface of propodeum generally smooth and shining, but one pair of rugulae running from metanotal groove to tips of propodeal spines. Dorsal surface of petiole smooth and shining. Lateral surface of petiole generally smooth, without longitudinal rugulae. Dorsal and lateral surfaces of postpetiole smooth and shining.

Standing pilosity sparse. Dorsal face of head with suberect setae sparsely. Clypeus with two pairs of long setae in anterior portion, one directed upward and the other downward. Anterior clypeal margin with one pair of long setae medially and short setae laterally. Scapes with suberect setae mixed with two to three long setae. Mesosoma with four pairs of long erect and stout setae (ps1PN, psaMN, pspMN, and ps1PS) that are much longer than other erect setae. Posterolateral tubercles of petiole posteriorly with two pairs of stout setae. Postpetiole with three pairs of setae on disc anteriorly, posteriorly, and laterally. Fourth abdominal tergite with erect setae sparsely, and short decumbent setae sparsely.

Body bicolored, head and gaster with brown, mesosoma, petiole and postpetiole with yellow. All flagellar segments yellow.

Comments: In the worker this species can be distinguished from all other members of the C. quadriruga group by the distinct compound eyes, V-shaped metanotal groove in lateral view, large propodeal spiracles touching metapleural gland bulla, long propodeal spines (PSL 0.08–0.11), and bicolored body. This species is similar to C. philippinensis , but can be distinguished from it by the scape with two to three erect setae and decumbent setae, and bicolored body.

Distribution: This species is known from Malaysia (Borneo) and Indonesia (Sumatra) ( Fig. 52 ).

Etymology: The specific name refers to the regions which the material is collected.

Material examined: INDONESIA: one worker, Ulu Gadut , nr. Padang, W. Sumatra, 27–30.viii.1985 (Sk. Yamane) ; MALAYSIA: seven workers, Maliau Basin (riparian forest), Sabah, Borneo (300 m alt.), 10.xi.2011 (ex carton cover) (SB11-SKY-38) (Sk. Yamane) .

Figures

Figure 52. Geographical distribution of the species of the C. quadriruga group.

Figures 120–123. Body in lateral view. 120, Crematogaster suehiro, worker [Mt. Omoto, Ishigaki Island, Japan]; 121, Crematogaster sundalandensis, worker [Maliau Basin (riparian forest), Sabah, Borneo, E. Malaysia]; 122, Crematogaster vieti, worker [near Forestry Station, Khe Kem, Pu Mat National Park, Nghe An, Vietnam]; 123, Crematogaster vieti, intermediate worker [near Forestry Station, Khe Kem, Pu Mat National Park, Nghe An, Vietnam].