Tetramorium impressum

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Tetramorium impressum
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Tetramorium
Species: T. impressum
Binomial name
Tetramorium impressum
(Viehmeyer, 1925)

Tetramorium impressum casent0280871 p 1 high.jpg

Tetramorium impressum casent0280871 d 1 high.jpg

Specimen Labels

Tetramorium impressum is common in newly rehabilitated sand mines in WA (pers. obs.; also mentioned but not named in Bisevac and Majer 1999) where it may collect seeds of grasses or herbs. This species is much less abundant in sites representing later successional stages. (Heterick 2009)

Identification

Heterick (2009) - Tetramorium impressum probably should be regarded as a species complex. Workers with black foreparts, yellow gaster and deeply impressed striae may well be genetically distinct from those that are reddish and more finely striate. However, the sculpture and shape of the node are identical in the two groups. Both forms also key out at T . impressum using Bolton’s (1977) taxonomic key to Australian Tetramorium species. All are widespread throughout the SWBP, WA.

Bolton (1977) - This is one species which I strongly suspect may be a composite, with more than one sibling species concealed in it. The variation in size, development of frontal carinae and antennal scrobes, and the variation of sculptural intensity all suggest that this species needs closer attention than I can give it at the present time. The holotype of impressum lies at the lower end of the size range given above.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Australasian Region: Australia (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 New General Catalogue, a catalogue of the world's ants.

  • impressum. Xiphomyrmex impressus Viehmeyer, 1925a: 30 (w.) AUSTRALIA. Combination in Tetramorium: Bolton, 1977: 138.

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

Description

Worker

Bolton (1977) - TL 2.9-4.1, HL 0.76-1.02, HW 0.72-1.00, CI 92-98, SL 0.52-0.68, SI 69-77, PW 0.54-0.72, AL 0.90-1.22 (15 measured).

Mandibles with varying sculpture, usually weakly striate but more rarely almost smooth. Frontal carinae weak and short, the anterior portion with a narrow, raised flange which extends back to the level of the eyes at most. Behind the level of the eyes the frontal carinae are absent or are in no way separable from the remainder of the cephalic sculpture. Antennal scrobes shallow and very weak or virtually absent, in larger individuals much less distinct than in smaller. Propodeal spines stout and acute, the metapleural lobes acute, elongate-triangular in shape. Petiole in profile relatively high and narrow (Fig. 69), with the dorsal length less than the height of the tergal portion of the node. Dorsal head finely and usually quite regularly longitudinally rugulose, the spaces between rugulae reticulate-punctate. Dorsal alitrunk predominantly longitudinally rugulose but with some cross-meshes, which are usually conspicuous on the pronotum. Spaces between rugulae punctate. Dorsal surfaces of petiole and post petiole coarsely sculptured with a mixture of rugosity and puncturation, the base of the first gastral tergite often feebly reticulate or punctulate but smooth in some specimens. All dorsal surfaces of head and body with numerous erect or suberect hairs. Colour ranging from yellow-brown to mid-brown, usually with the gaster lighter in shade than the alitrunk.

Type Material

References