Monomorium afrum

Every Ant Tells a Story - And Their Stories Are Here
Jump to navigation Jump to search
Monomorium afrum
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Solenopsidini
Genus: Monomorium
Species: M. afrum
Binomial name
Monomorium afrum
André, 1884

Mafrumcasent0915412 p 1 high.jpg

Mafrumcasent0915412 d 1 high.jpg

Specimen Labels

Synonyms

Arnold (1916) records that afrum forms populous nests in the soil, generally in exposed or sunny situations. Wheeler (1922) notes that the ants appeared in large numbers at the carcase of a bird. Whether scavenging represents the main feeding method of afrum or whether they are opportunists, both scavenging and indulging in active predation when possible, is not known.

Identification

Bolton (1987) - A widely distributed and very conspicuous species, afrum is easily identified within the salomonis-group by the combination of characters noted in the descrpition. The shape of the posteroventral occipital angles is unique in the group and immediately isolates afrum.

Within the informal aggregation of species termed the opacum-complex afrum also separates from two other members by its lack of pilosity on the alitrunk, which is present in Monomorium junodi and Monomorium albopilosum.

The female of afrum shows some modifications characteristic of the socially parasitic species Monomorium santschii and Monomorium effractor, and may itself found new colonies by a temporary socially parasitic process.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Burkina Faso, Central African Republic, Democratic Republic of Congo, Eritrea, Ethiopia, Ghana, Ivory Coast, Kenya, Rwanda, Sudan (type locality), United Republic of Tanzania, Zimbabwe.

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Queen

Nomenclature

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

  • afrum. Monomorium afrum André, 1884a: 244 (w.) SUDAN. [Also described as new by André, 1884b: 540.] Arnold, 1926: 226 (q.); Wheeler, G.C. & Wheeler, J. 1955c: 124 (l.). Combination in M. (Xeromyrmex): Wheeler, W.M. 1922a: 868. Senior synonym of asmarensis, fultor: Bolton, 1987: 334.
  • asmarensis. Monomorium afrum var. asmarensis Forel, 1910c: 250 (w.m.) ETHIOPIA. Junior synonym of afrum: Bolton, 1987: 334.
  • fultor. Monomorium afrum var. fultor Forel, 1913b: 332 (w.) DEMOCRATIC REPUBLIC OF CONGO. Junior synonym of afrum: Bolton, 1987: 334.

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

Description

Worker

Bolton (1987) - TL 3.6-4.3, HL 0.84-1.00, HW 0.66-0.80, CI 78-82, SL 0.72-0.85, SI 103-108, PW 0.46-0.52, AL 1.04-1.26 (35 measured).

Median portion of clypeus with its anterior free margin indented medially, the extent of the indentation varying in different populations from a narrow deep notch to a broad and quite deep concavity. Maximum diameter of eye 0.24-0.27 x HW, and with 10-12 ommatidia in the longest row. With head in profile the posteroventral angles bluntly right-angled or acute and narrowly rounded; not evenly broadly convex. Viewed from above and behind the posteroventral occipital angles are prominent and acute. Metanotal groove narrowly impressed. Dorsum of propodeum longitudinally impressed, the lateral margins of the impression diverging from front to back and frequently represented by a pair of sharp carinae, though in others the margins are merely bluntly rounded. Node of petiole in dorsal view with its posterior face shallowly transversely concave; degree of concavity varying between samples.

Head, alitrunk, petiole and postpetiole sharply and densely reticulate-punctate everywhere. First gastral tergite finely shagreenate, the sculpture sometimes fading apically on the sclerite. Head without standing hairs on dorsal surface behind level of frontal lobes or at most with a single pair mid-dorsally. Alitrunk without standing hairs; petiole with one pair, postpetiole with 1-2 pairs of backward directed hairs. First gastral tergite hairless except for the apical transverse row; these are usually appressed and may even be absent.

Colour uniform medium to dark brown, sometimes the gaster darker than the head and alitrunk. A widely distributed and very conspicuous species, afrum is easily identified within the salomonis-group by the combination of characters noted above . The shape of the posteroventral occipital angles is unique in the group and immediately isolates afrum.

Within the informal aggregation of species termed the opacum-complex afrum also separates from two other members by its lack of pilosity on the alitrunk, which is present in junodi and albopilosum.

Type Material

Bolton (1987) - Syntype workers, Sudan: Atbara (Magretti) (Musee National d'Histoire Naturelle) (examined).

References