Crematogaster sewardi

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Crematogaster sewardi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Crematogaster
Species: C. sewardi
Binomial name
Crematogaster sewardi
Forel, 1901

Crematogaster sewardi casent0908464 p 1 high.jpg

Crematogaster sewardi casent0908464 d 1 high.jpg

Specimen Labels

This species has been found in a variety of habitats. Little is know about its biology.

Identification

A member of the subgenus Physocrema. Hosoishi and Ogata (2009) - This species is very similar to Crematogaster ampullaris, but can be distinguished by the dorsal outline of the mesosoma and the depth of the metanotal groove. The MHNG syntypes were lighter colored than normal, but otherwise match the characters of the specimens examined.

Among the Physocrema species, Crematogaster ampullaris, Crematogaster difformis, and C. (P.) sewardi are very similar to each other. Crematogaster (P.) sewardi is widely distributed in South East Asia, but almost all have been referred to as C. (P.) difformis in the past. It is also likely that C. (P.) sewardi has been misidentified as C. (P.) difformis in the literature (Attygalle et al. 1989; Gay & Hensen, 1992; Ito et al. 2001; Jaitrong & Nabhitabhata, 2005; Jones et al. 2005). Based on the key C. (P.) difformis can be easily distinguished from ampullaris and sewardi, but the latter two species are very similar to each other and have been frequently confused. Crematogaster (P.) difformis and C. (P.) sewardi are geographically sympartric in the Malay Peninsula and Borneo, whereas C. (P.) ampullaris and C. (P.) sewardi are allopatric. Crematogaster (P.) ampullaris is found in Sulawesi, Timor and Philippines, and C. (P.) sewardi in Indochina, Malay Peninsula, Borneo, Sumatra, Krakatau Island, Java, Bali and Lombok.

Keys including this Species

Distribution

Crematogaster (P.) sewardi is the most wide-ranging species of the subgenus Physocrema. This species ranges from Thailand to Malaysia (Peninsula and Borneo) and to Indonesia (Kalimantan, Sumatra, Krakatau Island, Java, Bali and Lombok).

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo (type locality), Indonesia, Krakatau Islands, Malaysia.
Oriental Region: Thailand, Vietnam.


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • sewardi. Crematogaster deformis r. sewardi Forel, 1901h: 64 (w.q.) BORNEO. Combination in C. (Physocrema): Emery, 1922e: 140. Raised to species: Hosoishi & Ogata, 2009a: 7. See also: Hosoishi & Ogata, 2009b: 28.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Hosoishi and Ogata (2009) - HW 0.85–1.32; HL 0.77–1.22; CI 105–111; SL 0.70–0.96; SI 72–83; EL 0.16–0.24; PW 0.51–0.74; WL 0.96–1.40; PSL 0; PtL 0.28–0.42; PtW 0.21–0.36; PtH 0.15–0.22; PpL 0.19–0.28; PpW 0.23–0.34; PtHI 52–57; PtWI 74–86; PpWI 113–129; WI 94–116 (Three workers measured).

Workers with pronounced size polymorphism.

Scape not reaching posterior corner of head in large workers.

In lateral view, dorsal profile of promesonotum convex; propodeum distinctly raised relative to promesonotum. Anterior margin of pronotal collar slightly concave in dorsal view. Metanotal groove convex posteriorly in dorsal view in large workers, deep and situated posteriorly to the posterior ridge of pronotum in lateral view; thorax strongly constricted in middle in dorsal view. In dorsal view, some longitudinal rugulae connecting between mesonotum and propodeum; the boundary distinct. Propodeal spiracle situated away from the metapleural gland orifice, the distance between them much greater than the propodeal spiracle diameter. Propodeal spines absent.

Clypeus sculptured with longitudinal rugulae.

Standing pilosity sparse on dorsal face of head, abundant on promesonotum. Dorsal face of head with decumbent setae. Clypeus with short setae. Fourth abdominal tergite with appressed setae. Dorsal setae on fourth abdominal tergite directed posteriorly.

Body color black.

Type Material

Hosoishi and Ogata (2009) - LECTOTYPE worker (top specimen of two on one pin) (by present designation) and one paralectotype worker and queen from MALAYSIA: Borneo (H. Seward) (Musee d'Histoire Naturelle Genève) [examined].

References