Crematogaster quadriruga,

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 : 594-595

CREMATOGASTER QUADRIRUGA FOREL, 1911c STAT. NOV.

( FIGS 114, 115 )

Crematogaster biroi var. quadriruga Forel, 1911c: 455 ;

syntype workers, Kerr, Thailand (M. Waldo) ( MHNG, examined) . One syntype worker (top specimen of three on one pin) in MHNG here designated Lectotype.

Crematogaster biroi var. quadriruga ; Emery, 1922: 132 [Combination in C. ( Orthocrema )].

Worker measurements (n = 8): HW 0.46–0.50; HL 0.48– 0.51; CI 94–100; SL 0.44–0.48; SI 94–100; EL 0.11– 0.12; PW 0.27–0.31; WL 0.54–0.60; PSL 0.11–0.13; PtL 0.17–0.22; PtW 0.14–0.17; PtH 0.13–0.15; PpL 0.12– 0.17; PpW 0.15–0.18; PtHI 68–79; PtWI 74–85; PpWI 100–145; WI 100–113.

General description of worker: Workers monomorphic, but intermediate worker as large as queen.

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 with ridges laterally. Mesonotal dorsum with lateral ridges that irregularly extend posteriad to tips of propodeal spines. Pronotum and mesonotum in lateral view not clearly forming continuous dorsal outline; mesonotal dorsum higher anteriorly. Metanotal groove in dorsal view transverse, almost straight in median portion, forming deep concavity that is laterally margined by lamellate ridges. Propodeal spiracles oval, situated at posterolateral corners of propodeum, apart from 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 with short process that is slightly higher than posterior margin of petiole disc in lateral view. Subpetiolar process developed as acute process. 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 distinct pair of longitudinal longer rugulae and one pair of shorter rugulae laterally; longer rugulae not extending to posterior clypeal margin. Dorsal and lateral surfaces of pronotum smooth and shining; anterolateral shoulders of pronotum with longitudinal rugulae. Mesopleura weakly punctuate, but seems smooth and shining. Dorsal surface of propodeum generally smooth and shining, but with longitudinal rugulae anteriorly. Dorsal and lateral surfaces of petiole smooth and shining. Dorsal and lateral surfaces of postpetiole smooth and shining.

Standing pilosity sparse. Dorsal face of head with erect 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 and decumbent setae. Mesosoma with five to six pairs of long erect and stout setae (ps1PN, psaMN, pspMN, ps1PS, and one to two ps2PS) that are much longer than other erect setae. Posterolateral tubercles of petiole posteriorly with one pair of stout long setae and one pair of short setae laterally. Postpetiole with three pairs of setae on disc anterodorsally, anterolaterally and posteriorly. Fourth abdominal tergite with erect setae abundantly, and short appressed setae sparsely.

Body bicolored with head, mesosoma, petiole, postpetiole and first gater yellow and with the remains of the gaster brown. All flagellar segments yellow.

Intermediate worker measurements (n = 2): HW 0.65– 0.68; HL 0.66–0.68; CI 98–100; SL 0.60–0.61; SI 90– 92; EL 0.17; PW 0.48–0.51; WL 0.89–0.92; PSL 0.15; PtL 0.35; PtW 0.25–0.26; PtH 0.23–0.25; PpL 0.21– 0.22; PpW 0.28–0.29; PtHI 66–71; PtWI 71–74; PpWI 131–133; WI 111–112.

Description of intermediate worker: With worker character conditions, except as follows.

Three ocelli present.

Mesonotum strongly convex in lateral view. Posteri- or face of mesonotum steeply sloping so that in lateral view dorsal outline of promesonotum not smoothly arched.

Subpetiolar process developed as blunt process.

Dorsal surface of pronotum generally smooth, but with feeble rugulae. Dorsal surface of propodeum weakly punctuated with longitudinal rugulae. Lateral surface of petiole weakly sculptured. Dorsal surface of postpetiole smooth and shining.

Posterolateral tubercles of petiole with three to four pais of stout long setae posteriorly. Fourth abdominal tergite with erect setae abundantly, and short appressed setae sparsely.

Body usually bicolored with head, mesosoma, petiole, postpetiole and first gater yellow and with remains of gaster brown to black.

Comments: In the worker this species can be distinguished from all other members of the C. quadriruga group by the distinct compound eyes, propodeal spiracles small and apart from metapleural gland bulla, and petiole with subparallel sides in dorsal view. This species is similar to C. suehiro , but can be distinguished from it by longitudinal rugulae on clypeus not extending to posterior clypeal margin, bicolored body, petiole with subparallel sides in dorsal view.

Specimens from northern part of Thailand (Chiang Mai) differ from other specimens in having the developed rugulae on promesonotum, slightly large propodeal spiracles and slightly broader petiole with sculptured surface. Single specimen from Laos has erect longer setae on pronotal shoulders medially. Some specimens from Bokor National Park, Cambodia differ in having yellow-colored gaster.

Distribution and biology: This species is known from Laos, Cambodia, Thailand and Indonesia (N. Sumatra) ( Fig. 52 ). This species inhabits disturbed to developed forests, and nests in dead twigs on trees.

Material examined: CAMBODIA: six workers, Permanental Sample Plots , Kampong Thom, 9.i.2010 (SH10-Cam-20) (S. Hosoishi) ; two workers, Community forest , Kampong Chhnang, 27.xi.2010 (bamboo) (SH10-Cam-198) (S. Hosoishi) ; one worker, Kampong Thom, 20.xi.2010 ( TUS arboreal) (S. Hosoishi) ; 12 workers, Bokor National Park (870 m alt.), Kampot, 9–11.xii.2011 (Winkler 50 cm × 50 cm quadrat) (S. Hosoishi & S.-H. Park) ; INDONESIA: six workers, Pulau Weh, off Banda Aceh, Aceh, Sumara (disturbed forest), 27.xi.2012 (dead leaves on tree) ( SU12 -SKY-208) (Sk. Yamane) ; LAOS: one worker, Phang Dang Vil., Pak- Gnam Distr., Vientinane Prov. (350 m alt.), 13.vi.2010 (leaf litter) (Sk. Yamane) ; THAILAND: two workers, Campus of Chiang Mai Univ., Chiang Mai Prov., N. Thailand , 10.vi.2001, (Eg 01-TH-165) (K. Eguchi) ; one worker, Doi Chiang Dao, Chiang Mai Prov., N. Thailand , 9.vi.2001, (Eg 01-TH-140) (K. Eguchi) ; one worker, Sakaerat lowland forest ( DEF), Nakornratchasima , NE Thailand, 10.vii.1999, (Sk. Yamane) ; 15 workers, Residental area, Bang Khean Distr., Bangkok, C. Thailand , 25.viii.2003, (TH03-SKY-102) (dry dead wood) (Sk. Yamane) ; three workers, Lum Jang Wat , E. Thai., 7.xii.2005, (SH05-Tha-51) (S. Hosoishi) ; three workers, Maegar , Phayao, 30.iii.1990, (no collector’s name) ; four workers, Kaeng Krachan NP (320 m alt.), Phetchaburi Prov. (ex suspended dead twig) (TH14-SKY-10) (Ban Kr. C. HQ) ; three workers, Sa i Khao, Pattani Prov., S. Thailand , 25.viii.1998, (Sk. Yamane) ; six workers and two intermediate workers, PSU forest, Hat Yai , Songkhla Prov., 22.x.2011 (dead twig) (TH11-SKY- 168) (Sk. Yamane) : three workers, Khlong Saeng, Ratchaprapha , Surat Thani, 15.x.2011 (dead twig on tree) (TH11-SKY-139) (Sk. Yamane) .

Figures

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

Figures 112–119. Body in lateral view. 112, Crematogaster osakensis, worker [Hiraodai Karst Plateau, Fukuoka, Japan]; 113, Crematogaster philippinensis, worker [Mt. Mayon, Luzon Island, Philippines]; 114, Crematogaster quadriruga, worker [Lum Jang Wat, E, Thailand]; 115, Crematogaster quadriruga, intermediate worker [PSU forest, Hat Yai, Songkhla Prov., S. Thailand]; 116, Crematogaster reticulata, worker [Ulu Gombak, Selangor, W. Malaysia]; 117, Crematogaster reticulata, intermediate worker [Datfa Waterfall, Tai Rom Yen National Park, Surat Thani Prov., S. Thailand]; 118, Crematogaster schimmeri, worker [Pilam, Taiwan]; 119, Crematogaster storki, worker [Dumoga-Bone National Park, Utara, Sulawesi, Indonesia].