Tetramorium amaurum

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Tetramorium amaurum
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Tetramorium
Species: T. amaurum
Binomial name
Tetramorium amaurum
Bolton, 1980

Tetramorium amaurum P casent0901161.jpg

Tetramorium amaurum D casent0901161.jpg

Specimen Label

Known from only a few specimens. The two non-type workers were collected, from pitfall traps, in a montane grassland and a riparian area.

Identification

Bolton (1980) - The four species closely related to amaurum, namely Tetramorium subcoecum, Tetramorium warreni, Tetramorium traegaordhi and Tetramorium typhlops, only have a single ommatidium or two ommatidia in the eye, whereas T. amaurum has 3-5. Beside this, T. warreni and T. typhlops are both minute species with HW < 0-50, SL < 0-35, and completely lack frontal carinae. In T. subcoecum frontal carinae are vestigial or absent but in T. traegaordhi they are about as strongly developed as in T. amaurum. Apart from the size of the eye, T. traegaordhi differs from T. amaurum by having the petiole node distinctly transverse in dorsal view, much broader than long, and by having longer, more conspicuous body pilosity than T. amaurum. To illustrate this, with the body in profile the longest hairs on both the alitrunk and the first tergite are distinctly longer than the maximum width of the hind tibia in T. traegaordhi, shorter than the hind tibial width in T. amaurum.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: South Africa, Zimbabwe (type locality).

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 Online Catalogue of the Ants of the World.

  • amaurum. Tetramorium amaurum Bolton, 1980: 286, fig. 69 (w.) ZIMBABWE.

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

Description

Worker

Holotype: TL 2.7, HL 0.70, HW 0.63, CI 90, SL 0.46, SI 73, PW 0.42, AL 0.72. Paratypes (8 measured): TL 2.6-3.1, HL 0.66-0.74, HW 0.60-0.66, CI 89-94, SL 0.44-0.50, SI 69-76, PW 0.38-0.46, AL 0.71-0.82.

Mandibles finely and faintly longitudinally striate, the sculpture not conspicuous. Anterior clypeal margin with a small median notch or impression. The central portion of the clypeus immediately behind the impression very shallowly transversely concave but the median carina running the length of the clypeus. Frontal carinae very feeble, no more than fine and narrow raised lines which end at the level of the eyes. Antennal scrobes absent. Eyes minute but quite conspicuous, of 3—4 poorly defined facets and much shorter than the maximum width of the scape. Maximum diameter of eye 0.05, about 0.08 x HW. Alitrunk in profile more or less evenly convex, with a very feeble and shallow impression at the metanotal groove that barely interrupts the outline. Propodeum armed with a pair of short triangular teeth which are about as long as their basal width. Metapleural lobes distinctly broader and very slightly longer than the propodeal teeth, lobate and rounded apically. Petiole in profile with the dorsal length less than the height of the tergal portion, both antero- and posterodorsal angles rounded. Petiole in dorsal view slightly broader than long and with all angles rounded, the dorsum merging into the sides, the anterior, and the posterior faces. Dorsum of head with a few feeble, scratch-like longitudinal rugulae which fade out before reaching the occipital region, which is only very lightly shagreened. Spaces between sparse rugulae on dorsum on head with a weak, superficial ground-sculpture. Dorsal surfaces of alitrunk, petiole, postpetiole and gaster unsculptured except for a few faint punctulations on the propodeum. Dorsal surfaces of head and body with sparse standing hairs but the middle and hind tibiae only with short pubescence which is decumbent to appressed. Colour yellow.

Paratypes: As holotype but eye with 3-5 facets, the limits of individual ommatidia generally difficult to see. Maximum diameter of eye 0.04-0.07, about 0.06-0.10 x HW.

Type Material

Holotype worker, Rhodesia: Redbank, 3.xii.1917 (G. Arnold) (The Natural History Museum). Paratypes, 10 workers with same data as holotype (BMNH; Museum of Comparative Zoology; Natural History Museum of Zimbabwe).

References

References based on Global Ant Biodiversity Informatics

  • IZIKO South Africa Museum Collection