Tetramorium cristatum

AntWiki: The Ants --- Online
Jump to navigation Jump to search
Tetramorium cristatum
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Tetramorium
Species: T. cristatum
Binomial name
Tetramorium cristatum
Stitz, 1910

Tetramorium cristatum casent0217222 p 1 high.jpg

Tetramorium cristatum casent0217222 d 1 high.jpg

Specimen Labels

Synonyms

Known from open areas such as savannah and farmland, collections have all been from the ground.

Identification

Bolton (1980) - A member of the T. cristatum species complex in the Tetramorium bicarinatum species group. Five species of the bicarinatum-group, as represented in the Ethiopian region, are large. These are Tetramorium gazense, Tetramorium emeryi, Tetramorium erectum, T. cristatum and Tetramorium notiale. Of these the first three are uniform brown or blackish brown in colour whilst T. notiale is uniformly orange-brown or yellowish brown with the gaster the same colour as or lighter than the alitrunk and head. Tetramorium cristatum, with its strongly contrasting dark gaster, is thus quite distinct and easy to spot. Only Tetramorium peutli in the bicarinatum-group shares the colour pattern of T. cristatum among the smaller native African species but here the postpetiole lacks a rugoreticulum dorsally and the basigastral costulae are very reduced or absent. A similar colour-scheme is present in Tetramorium bicarinatum but here the mandibles are sculptured with dense fine striae whereas they are smooth in T. cristatum and its immediate allies. The closest relatives of T. cristatum are discussed under T. gazense.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Angola, Democratic Republic of Congo, Ghana, Guinea, Ivory Coast, Kenya, Sudan, Togo (type locality), Uganda, United Republic of Tanzania, Zimbabwe.

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Worker

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • cristatum. Tetramorium guineense var. cristatum Stitz, 1910: 144 (w.) TOGO. Raised to species, senior synonym of medje and material of the unavailable name ebangense referred here: Bolton, 1980: 268.
  • medje. Tetramorium guineense subsp. medje Wheeler, W.M. 1922a: 192 (w.) DEMOCRATIC REPUBLIC OF CONGO. Junior synonym of cristatum: Bolton, 1980: 268.

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

Description

Worker

Bolton (1980) - TL 4.1—5.1, HL 0.94-1.20, HW 0.78-1.02, CI 81-87, SL 0.60-0.76, SI 73-81, PW 0.59-0.76, AL 1.08—1.40 (15 measured).

Mandibles smooth and shining with scattered pits. Anterior clypeal margin with a distinct median notch or impression. Clypeus with three strong longitudinal carinae, sometimes also with 1-2 more carinae which are, however, much more feeble. Sides of median portion of clypeus bounded by a narrow raised longitudinal rim or flange which is continuous with the frontal carinae over the antennal insertions; the flanges indented at about the midlength of the clypeus. Frontal carinae long and strong, reaching back almost to the occipital margin but posteriorly tending to merge into the reticular sculpture. Maximum diameter of eye 0.22-0.28, about 0.27-0.32 x HW. Propodeal spines long and strong, with a marked tendency to be slightly upcurved along their length; only rarely are they more or less straight. Metapleural lobes elongate-triangular and upcurved, acute apically. Petiole node in profile roughly rectangular in shape, the anterior and dorsal surfaces meeting in a right-angle or near right-angle and the dorsum behind this shallowly convex. Posterodorsal angle of node more acute than anterodorsal, usually sharp and slightly overhanging the feebly concave posterior face. In dorsal view the petiole showing:some variation in width, usually somewhat longer than broad but in several specimens only about as long as broad. Dorsum of head irregularly longitudinally rugose to level of eyes, often with some cross-meshes. Behind the level of the eyes the head strongly reticulate-rugose. Dorsal alitrunk reticulate-rugose and with a transverse, raised rugular crest at the promesonotal junction, the reticulum sometimes stronger in front of this ridge than behind. Petiole and postpetiole reticulate-rugose dorsally. First gastral tergite with conspicuous, fine dense basal costulae. All dorsal surfaces with numerous strong erect or suberect acute hairs. Hind tibiae with quite dense subdecumbent to decumbent short pilosity. Head, alitrunk and pedicel segments varying from bright orange-yellow to glossy orange-brown, the gaster always much darker, dark brown to blackish brown but is generally with the extreme base of the gaster (where the costulae are densest) distinctly paler.

Type Material

Bolton (1980) - Syntype workers, Togo: Bismarckburg (Conradt) (Berlin Museum für Naturkunde der Humboldt-Universität) [examined]. Tetramorium guineense subsp. medje. Syntype workers, ZAIRE: Medje, from stomach of toad (Lang & Chapin) (Museum of Comparative Zoology) [examined]. Tetramorium guinense [sic] st. cristatum var. ebangense Syntype workers, ANGOLA: Ebanga (A. Monard) (Naturhistorisches Museum, Basel) [examined]. [Name unavailable.]

References

References based on Global Ant Biodiversity Informatics

  • Bernard F. 1953. La réserve naturelle intégrale du Mt Nimba. XI. Hyménoptères Formicidae. Mémoires de l'Institut Français d'Afrique Noire 19: 165-270.
  • Bolton B. 1980. The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Ethiopian zoogeographical region. Bulletin of the British Museum (Natural History). Entomology 40: 193-384.
  • Garcia F.H., Wiesel E. and Fischer G. 2013.The Ants of Kenya (Hymenoptera: Formicidae)—Faunal Overview, First Species Checklist, Bibliography, Accounts for All Genera, and Discussion on Taxonomy and Zoogeography. Journal of East African Natural History, 101(2): 127-222
  • Stitz H. 1910. Westafrikanische Ameisen. I. Mitteilungen aus dem Zoologischen Museum in Berlin 5: 125-151.
  • Weber N. A. 1943. The ants of the Imatong Mountains, Anglo-Egyptian Sudan. Bulletin of the Museum of Comparative Zoology 93: 263-389.