Monomorium firmum

AntWiki: The Ants --- Online
Monomorium firmum
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Solenopsidini
Genus: Monomorium
Species: M. firmum
Binomial name
Monomorium firmum
Santschi, 1926

Monomorium firmum casent0902234 p 1 high.jpg

Monomorium firmum casent0902234 d 1 high.jpg

Specimen Labels

A collection of this ant was made in miombo woodland. Monomorium firmum has only been collected a few times.


Bolton (1987) - A member of the M. schultzei complex in the M. monomorium species group. This relatively large yellow species is a conspicuous member of the complex. It is closest related to Monomorium vecte, also known from Zimbabwe, the two together being distinguished from the remaining schultzei-complex members which have relatively large propodeal spiracles by their dense pilosity. Of all schultzei-complex members in which the metanotal groove is broad and traversed by long conspicuous cross-ribs, and the propodeal spiracle is large, only firmum and vecte have 8 or more pairs of hairs on the promesonotal dorsum. Differences separating the two are noted under vecte.

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: -19.08333° to -19.08333°.

Tropical South

Distribution based on Regional Taxon Lists

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

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.



Images from AntWeb

Monomorium firmum casent0902234 d 2 high.jpg
Syntype of Monomorium firmumWorker. Specimen code casent0902234. Photographer Will Ericson, uploaded by California Academy of Sciences. Owned by NHMUK, London, UK.


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

  • firmum. Monomorium firmum Santschi, 1926b: 231 (w.) ZIMBABWE.
    • Type-material: syntype workers (number not stated).
    • Type-locality: Zimbabwe (“S Rhodesia”): Vumba Mts, Cloudlands, 6000 ft, 6-17.iv.1923 (G. Arnold).
    • Type-depositories: BMNH, NHMB.
    • Status as species: Ettershank, 1966: 89; Bolton, 1987: 389 (redescription); Bolton, 1995b: 262.
    • Distribution: Zimbabwe.

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



Bolton (1987) - TL 2.6-2.8, HL 0.58-0.66, HW 0.46-0.54, CI 79-83, SL 0.50-0.56, SI 100-109, PW 0.30-0.33, AL 0.70-0.76 (10 measured).

Clypeal carinae conspicuous, relatively close together, feebly divergent anteriorly and sometimes the carinae broken or interrupted at about their midlength. Space between the clypeal carinae shallowly transversely concave. Anterior margin of narrow prominent median section of clypeus weakly concave, the anterior and lateral margins of this section separated by blunt angles, without projecting denticles. Maximum diameter of eye 0.20-0.22 x HW and with 6-7 ommatidia in the longest row. With the head in full-face view the eyes close to the midlength of the sides, usually the posterior margins of the eyes at or even slightly behind the midlength of the sides. Antennal scapes, when laid straight back from their insertions, reaching or slightly surpassing the occipital margin. Sides of head evenly shallowly convex in full-face view and the occipital margin shallowly convex or the median area more or less flat. Promesonotum in profile a low convexity, descending behind to the broad impressed metanotal groove which is traversed by long strong cross-ribs. Propodeal spiracle large and conspicuous. Petiole node in profile relatively low, broadly subconical and with both anterior and posterior faces weakly convex. Subpetiolar process a conspicuous lobe. Postpetiole lower than petiole, smaller and more broadly rounded in profile. All dorsal surfaces of head and body with numerous standing hairs, the promesonotum with more than 8 pairs. Mostly unsculptured and shining except for scattered hair-pits, but the metanotal groove crossribbed and the mesopleuron in some with traces of weak reticulate sculpture. Colour yellow.

Type Material

Bolton (1987) - Syntype workers, Zimbabwe: Vumba Mts, 6000 ft (1830 m), Cloudlands 6-17.iv.1923 (G. Arnold) (The Natural History Museum; Naturhistorisches Museum, Basel) [examined].


References based on Global Ant Biodiversity Informatics

  • IZIKO South Africa Museum Collection