Crematogaster reticulata

This species inhabits developed forests and nests in dead twigs or in dead leaves on trees.

Identification
Hosoishi and Ogata (2016) - In the worker this species can be distinguished from all other members of the Crematogaster biroi group by the distinct compound eyes, strongly sculptured dorsal surface of head, and petiole squared without angulate anterolateral corners. This species is very similar to Crematogaster schimmeri, but can be distinguished from it by the propodeal spiracles apart from metapleural gland bulla, petiole squared without angulate anterolateral corners.

Distribution
S. Thailand and Malaysia (Peninsula and Borneo) and Brunei.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Brunei Darussalam, Indonesia, Malaysia. Oriental Region: Thailand.

Nomenclature

 *  reticulata. Crematogaster reticulata Hosoishi, 2009: 259, figs. 1-3 (w.) MALAYSIA.

Worker
Hosoishi and Ogata (2016) - (n=7) HW 0.40–0.46; HL 0.40–0.46; CI 96–103; SL 0.36–0.42; SI 84–91; EL 0.10–0.11; PW 0.27–0.30; WL 0.46–0.57; PSL 0.09–0.14; PtL 0.15–0.17; PtW 0.12–0.14; PtH 0.11–0.13; PpL 0.09–0.12; PpW 0.14–0.15; PtHI 67–76; PtWI 75–87; PpWI 122–155; WI 107–111.

Workers monomorphic, but intermediate workers as large as queen (see below). 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 weakly convex or almost straight 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 almost straight anterior margin in dorsal view, distinctly lower than pronotum in lateral view. Pronotal dorsum with ridges laterally. Mesonotal dorsum with lateral ridges. Pronotum and mesonotum in lateral view not clearly forming 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, apart from metapleural gland bullae. Propodeal spines developed, longer than diameter of propodeal spiracles, in dorsal view directed posteriad.

Petiole in dorsal view with parallel sides and angulate shoulders 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 slightly wider than petiole, weakly bilobed posteriorly but without longitudinal sulcus. Subpostpetiolar process developed as acute process.

Integument essentially sculptured. Dorsal surface of head sculptured reticulately. Mandibles with feeble rugulae and smooth interspaces. Clypeus weakly sculptured with longitudinal rugulae; longer rugulae extending to posterior clypeal margin. Anterolateral shoulders of pronotum with rugulae. Lateral surface of pronotum sculptured in higher portion, but relatively smooth and shining in lower portion. Pronotum and mesonotum with longitudinal rugulae and sculptured interspaces. Mesopleura sculptured, but relatively smooth in central areas. Rugula on higher portion of mesopleura extending to small pit of mesothoracic spiracles. Dorsal surface of propodeum sculptured. Dorsal and lateral surfaces of petiole sculptured. Dorsal and lateral surfaces of postpetiole sculptured.

Standing pilosity sparse. Dorsal face of head with several pairs (c. 9) of erect and stout long setae, and short and decumbent 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 some pairs (three to four) of short setae laterally. Scapes with decumbent to appressed setae. Mesosoma with five pairs of long erect and stout setae (ps1PN, ps2PN, psaMN, pspMN, and ps2PS) that are much longer than other erect setae. Posterolateral tubercles of petiole posteriorly with one pair of stout long setae. Postpetiole with three pairs of stout long setae on disc anterodorsally, anterolaterally and posteriorly. Fourth abdominal tergite with several pairs (c. 12) of erect and stout setae, and short appressed setae sparsely.

Body yellow-brown. All flagellar segments yellow.

Intermediate. (n=2) HW 0.66–0.75; HL 0.63–0.69; CI 105–109; SL 0.49–0.54; SI 72–74; EL 0.16–0.18; PW 0.49–0.56; WL 0.80–0.94; PSL 0.16–0.18; PtL 0.28–0.32; PtW 0.23–0.26; PtH 0.18–0.23; PpL 0.17–0.20; PpW 0.27–0.30; PtHI 64–72; PtWI 81–82; PpWI 150–159; WI 115–117.

With worker character conditions, except as follows.

Head subquadratic. Three ocelli present.

Mesonotum highly convex in lateral view. Pronotum not clearly forming same dorsal outline with mesonotum in lateral view, but posterior face forming oblique slope to metanotal groove. Propodeal spiracles oval.

Subpetiolar process developed as small tubercle.

Mesosoma with nine to 11 pairs of erect and stout long setae; one ps1PN and one to two ps2PN, five to six pairs on mesonotal ridges, two pairs on propodeal spines. Posterolateral tubercles of petiole with two pairs of stout long setae posteriorly. Postpetiole with four pairs of stout long setae on disc anterodorsally, anterolaterally and posteriorly.

Type Material
Hosoishi and Ogata (2016) - Holotype worker, Ulu Gombak, Selangor, Malaysia, 27.xi.2005 (SH05-Mal-01) (S. Hosoishi) (, examined) and ten paratype workers, same data as holotype (,, , , , examined).

Etymology
The specific epithet reticulata refers to the reticulated sculpture on this species, which form the reticulation on the head, mesosoma, petiole and postpetiole.

References based on Global Ant Biodiversity Informatics

 * Blaimer B. B. 2012. Acrobat ants go global  Origin, evolution and systematics of the genus Crematogaster (Hymenoptera: Formicidae). Molecular Phylogenetics and Evolution 65: 421-436.
 * Hosoichi S., and K. Ogata. 2016. Systematics and biogeography of the ant genus Crematogaster Lund subgenus Orthocrema Santschi in Asia (Hymenoptera: Formicidae). Zoological Journal of the Linnean Society 176: 547–606.
 * Hosoishi S. 2009.  A new species from Crematogaster the subgenus Orthocrema in Asia (Hymenoptera, Formicidae). Japanese Journal of Systematic Entomology. 15: 259-262.
 * Hosoishi S. and K. Ogata. 2009. A check list of the ant genus Crematogaster in Asia (Hymenoptera: Formicidae). Bull. Inst. Trop. Agr. Kyushu Univ. 32: 43-83.
 * Hosoishi, S. 2009. A new species from Crematogaster the subgenus Orthocrema in Asia (Hymenoptera, Formicidae). Japanese Journal of Systematic Entomology 15:259-262. [2009-06-30] PDF 131503
 * Li F. 2007. A Taxonomy Study on Genera Crematogaster and Myrmica from China (Hymenoptera:Formicidae:Myrmicinae). Guangxi Normal University, Guangxi, China. 58 pages.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58