Crematogaster khmerensis, Hosoishi & Ogata, 2017

Hosoishi, Shingo & Ogata, Kazuo, 2017, Phylogenetic analysis and systematic position of two new species of the ant genus Crematogaster (Hymenoptera, Formicidae) from Southeast Asia, European Journal of Taxonomy 370, pp. 1-17 : 9-11

Crematogaster khmerensis sp. nov.

urn:lsid:zoobank.org:act:D2CC1731-9989-4708-9513-36E1458CE012 Figs 4 A–D Diagnosis

Crematogaster khmerensis sp. nov. belongs to the subgenus Crematogaster sensu stricto ( Blaimer 2012b). This small-sized species of Crematogaster ants (HW 0.6–0.66; WL 0.63–0.69) is similar to C. pfeifferi sp. nov., but can be distinguished by the propodeal spiracles touching metapleural gland bulla, short propodeal spines (PSL 0.08–0.09), petiole broader anteriorly than posteriorly and undeveloped subpetiolar process.

Etymology

The specific name refers to the former kingdom name of Cambodia, the Khmer Empire.

Type specimens

Holotype

CAMBODIA: worker, Kampong Thom Province, 24 Nov. 2010, S. Hosoishi leg., (TUS arboreal SF3-1) ( KUMANT040 : deposited at THNHM).

Paratypes

CAMBODIA: 3 workers, same locality data as for holotype (TUS arboreal SF3-3, TUS arboreal SF3-6) (KUMANT041: deposited at BMNH; KUMANT042: deposited at CASC; KUMANT043: deposited at KUEC).

Measurements and indices

HW 0.60–0.66; HL 0.60–0.67; CI 97–102; SL 0.43–0.50; SI 69–76; EL 0.14–0.15; PW 0.35–0.40; WL 0.63–0.69; PSL 0.08–0.09; PtL 0.22–0.23; PtW 0.20–0.25; PtH 0.12–0.14; PpL 0.12–0.14; PpW 0.20–0.23; PtHI 52–64; PtWI 87–114; PpWI 154–167; WI 92–100 (holotype and three paratype workers measured).

Description

Worker

Workers presumably monomorphic.

Head subquadrate in full-face view, with rounded posterior corners and subparallel sides. Occipital carinae developed. Mandible with four teeth, apical tooth large. Anterior margin of clypeus convex; anterolateral margins of clypeus protruded anteriorly; posterior margin of clypeus rounded between frontal lobes. Frontal carinae almost parallel. Antennae 11-segmented; antennal club 3-segmented. Scape reaching posterior corner of head. Basal flagellar segment (antennal segment III) as broad as long. Compound eyes slightly projecting beyond lateral margins of head in full face view.

Pronotal shoulders angulate, but without distinct rugulae laterally. Mesonotal dorsum convex in lateral view. Pronotum and mesonotum not forming same dorsal outline in lateral view. Mesothoracic spiracle forms large pit concealed by posterior pronotal lobe. Metapleural gland opening slit-shaped. Propodeal spiracle large and circular, situated at posterolateral corners, touching metapleural gland bulla. Metanotal groove straight in dorsal view, deep and forming concave region between mesonotum and propodeum. In dorsal view, feeble longitudinal rugulae connecting between mesonotum and propodeum; the boundary distinct. Propodeal spines developed and directed vertically in lateral view.

Petiole scoop shaped, but flattened broader anteriorly, longer than broad; spiracle situated anteriorly midway between dorsal and ventral margin of petiole in lateral view, directed laterally. Subpetiolar process developed as a short lamellate denticle. Postpetiole without longitudinal median sulcus, but bilobed behind; spiracle situated anteriorly on lateral surface.

Dorsal surface of head mostly smooth or weakly shagreened. Clypeus mostly smooth and shining. Pronotal collar areolately sculptured. Promesonotum weakly punctate. Lateral surface of pronotum smooth and shining. Mesopleuron mostly smooth and shining, but sculptured on surrounding area. Anterodorsal surface of propodeum weakly punctate; posteior half smooth and shining. Lateral surface of propodeum smooth and shining. 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 appressed setae; one pair of erect setae on frontal lobes. Clypeus with one pair of erect setae. Anterior clypeal margin with two pairs of long setae mixed with short setae laterally. Scape with decumbent setae. Mesontum with appressed setae sparsely. Petiole with one pair of suberect setae posteriorly. Postpetiole with one pair of suberect setae posteriorly. Fourth abdominal tergite with short appressed setae sparsely.

Body color brown.

Queen and male

Queens and males of this species are unknown.

Distribution

This species is known only from the type locality in Cambodia ( Fig. 5 ).

Figures

Fig. 4. A–D. Crematogaster khmerensis sp. nov., worker. A. Body in lateral view. B. Full-face view of head. C. Dorsal view of mesosoma. D. Petiole and postpetiole in dorsal view. — E–H. — Crematogaster pfeifferi sp. nov., worker. E. Body in lateral view. F. Full-face view of head. G. Dorsal view of mesosoma. H. Petiole and postpetiole in dorsal view.

Fig. 5. Phylogeny and distribution of the Crematogaster borneensis-group, C. khmerensisi sp. nov., C. fruhstorferi, C. ssAUS5, C. mjobergi and the C. tetracantha-group. Closed circle indicates C. khmerensis sp. nov., closed square indicates C. pfeifferi sp. nov. It is noted that C. pfeifferi sp. nov. is not represented in the phylogeny.