Centromyrmex angolensis

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Centromyrmex angolensis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Centromyrmex
Species: C. angolensis
Binomial name
Centromyrmex angolensis
Santschi, 1937

Centromyrmex angolensis casent0417147 profile 1.jpg

Centromyrmex angolensis casent0417147 dorsal 1.jpg

Specimen labels

Recorded as being collected from termitaries of Apitermes and Protermes, though the range of prey is probably much wider.

Identification

A member of the feae species group. Closely related to Centromyrmex sellaris but worker and queen always with just a single spiniform seta at the inner apex of the metatibia, and always with a narrower head. In addition, the basal dentition of the mandible of angolensis can usually be distinguished from that of sellaris, as discussed under the latter name. (Bolton and Fisher 2008)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Angola (type locality), Cameroun, Central African Republic, Democratic Republic of Congo, Gabon, Ghana, Ivory Coast, Liberia.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

All of the species in the genus appear to be termitophagous and all are superbly adapted to this specialised predatory life style. Observations of some species have found them to be rather helpless when placed in an exposed, open situation. Weber described what happened when he found a worker “just beneath the soil surface under a thin cover of dead leaves”. The ant was “completely helpless when exposed to the daylight and writhed about when placed on the ground or in my palm. It made no attempt to run away, curling and uncurling without stinging, though it had a long, stout sting”. In other words, it seemed unable to walk when removed from its specialised habitat and placed on a surface where it could not use its specialised legs. If not discovered within a termite nest, individuals are occasionally found in the top soil or the root-mat below the leaf litter layer, where their short, powerful, spiny legs facilitate their movement. (Weber 1949, Bolton and Fisher 2008).

Castes

Queen

Nomenclature

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

  • angolensis. Centromyrmex constanciae var. angolensis Santschi, 1937d: 216 (w.) ANGOLA. Bolton & Fisher, 2008c: 15 (q.m.). Raised to species: Bolton & Fisher, 2008c: 15.

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

Description

Worker

Bolton and Fisher (2008) - TL 4.3-6.2, HL 0.76-0.98, HW 0.78-1.00, CI 98-103, ML 0.49-0.70, MI 63-71, SL 0.58-0.74, SI 69-76, PW 0.58-0.82, WL 1.26-1.70 (30 measured).

With characters of the genus and the feae group. Head capsule in full-face view usually appears slightly longer than broad, sometimes about as long as broad, CI 103 or usually less. Mandibles smooth with scattered small punctures. Masticatory margin of mandible with 7–10 small, low indistinct teeth, reduced to mere crenulations or even more or less smooth in the proximal half when worn. Basal angle of mandible rounded, frequently without trace of a basal tooth but sometimes with a vestigial tooth. Dorsum of head with scattered punctures on smooth cuticle; on sides of head the punctures denser than on dorsum, and also with weak striation within the antennal fossae and on the sides, especially anteriorly. Extent of the striate component is variable. Metatibia with only normal setae dorsally but its anterior surface, at the apex and approximately opposite the pectinate spur, with a single, much stouter and sometimes more darkly coloured piniform seta. Petiole node in dorsal view broader than long. Pronotal dorsum, and anterior mesonotum, with widely scattered broad, shallow punctures that may be almost effaced. Pronotum dorsally also usually with variable weak oblique or arched faint disorganised sculpture, almost effaced in some specimens. Colour yellow to light brown.

Queen

Bolton and Fisher (2008) - TL 6.0-6.4, HL 0.94-0.96, HW 0.98-1.02, CI 104-106, OI 31-32, ML 0.63-0.65, MI 66-68, SL 0.70-0.74, SI 71-73, PW 0.94-0.96, WL 1.88-1.94 (4 measured). Very similar to the worker but the head averaging slightly broader. The queen will run out successfully in the key to workers. The unique worker character of a single thickly spiniform seta at the anterior apex of metatibia is duplicted in the queen caste.

Type Material

Holotype worker, ANGOLA: Sangévé (A. Monard) (Naturhistorisches Museum Basel) [examined].

References