The Ants of Africa
Contents - Myrmicinae - MYRMICINAE Introduction

Genus Monomorium Mayr (1855: 452), also Syllophopsis Santschi (1915c: 259) and Trichomyrmex Mayr (1865: 19)


Diagnostic Features - Antennae 11- or 12-segmented, with a 3-segmented club. Median portion of clypeus with two distinct longitudinal carinae; clypeus may also be concave between the carinae on the anterior margin, the carinae then project as a pair of blunt teeth. Eyes present. Promesonotal suture absent, metanotal groove impressed. Propodeum unarmed. Petiole pedunculate, node high and rounded. Postpetiole node less voluminous than petiole node in profile and narrowly attached to the gaster.

Mayr (1861: 71) reiterated his earlier (1855) genus description, this is at {original description}. Mayr (1865: 19) defined genus Trichomyrmex, this is at {original description}. Emery (1915i: 190) listed what then were regarded as valid subgenera - see {original description}. Emery (1922e) later synonymised Mitara with the older name Lampromyrmex, itself now regarded as a synonym of Monomorium. Ettershank (1966) had Syllophopsis separate from Monomorium but noted that he had not examined any specimens of Syllophopsis. The revision by Bolton (1987) included synonymy of Syllophopsis, as defined by Santschi (1915c: 259) and further tackled by Santschi (1921c: 119) - see {original description} and {original description}.

Bolton (1987) extensively reviewed the Genus and his general conclusions are at {original description}. He chose to set aside the concept of subgenera, instead using a format of species-groups, with a subordinate level of species-complexes.

As a point of correction, Bolton (1987: 296) commented upon the subgenus Parholcomyrmex, as defined by Emery (1915i); writing that the name was - "also misspelled as Paraholcomyrmex later in the same publication". As the original text shows, it is obvious that Emery intended the name to be Paraholcomyrmex, literally (para-) similar to Holcomyrmex, as the name is printed in bold in the key, with the comment (translated) = male as Holcomyrmex.


1. Amendments following Heterick (2006) bringing four African species into synonymy under Malagasy species - M. leopoldinum under M. madecassum; M. binatu and M.exchao under M. termitobium; and, M. valtinum under M. hanneli. Also changes to M. mictilis with transfer of the junior synonym M. minutissimum to under M. exiguum.

2. Ward et al. (2014: 10) have resurrected the Genera Syllophopsis, containing species in the hildebrandti-group, and Trichomyrmex containing species in the scabriceps- and destructor-groups, from synonymy with Monomorium.
Syllophopsis from sub-Saharan Africa are arnoldi (revived from renaming as jonesi), cryptobia, elgonensis, malamixta, modesta, sersalata and thrascolepta.
Trichomyrmex from sub-Saharan Africa are - abyssinicus, destructor, emeryi, epinotale, mayri, oscaris and robustior.

Key to Monomorium species-groups and component species from sub-Saharan Africa

Notes on West African & Congo Basin species

Bolton (1987) recognised 145 valid species from the Afrotropical region but he recorded only 26 of those from West Africa, as defined in this work. Interestingly, this total of 26 was the same as that given by Bernard (1952), who noted a total of 76 from all Africa. Wheeler (1922) included a record of destructor from Ghana (but see my comments under oscaris and its variant). The work of Belshaw & Bolton (1994b) has added one species to the West African list (M. gabrielense) and three as yet unnamed species. Adding the species known from the Congo Basin has taken the total covered here to 43 species.

Five species, Monomorium abyssinicum (Forel), Monomorium balathir Bolton, Monomorium mayri (Forel), Monomorium areniphilum Santschi, and Monomorium subopacum (Smith) were known from the Sudan savannah or Sahelian region. Most records in the western end of that region were from Mali or Niger. Monomorium abyssinicum is known from further south in the Guinea savannah (Ghana and Nigeria). The latter two were recorded from Senegal, M. areniphilum had an unknown location (as Monomorium salomonis variety pullula, collector Claveau, in Santschi, 1919b); and M. subopacum from Saint-Louis, a northern coastal town (as Monomorium salomonis strain subopacum variety senegalensis or liberta (same specimens) and unnecessary replacements claveaui and santschiellum, collector also Claveau, in Santschi, 1913c). Only M. abyssinicum, areniphilum and subopacum are included in the key below.

Note there is a somewhat dubious species Monomorium senegalense Roger - type location Senegal (Roger, 1862c; Bolton, 1987, 1995). This is not listed or given in the key as it is known only from the original brief description, the specimens apparently having been lost. Possibly it is a senior synonym of Monomorium dakarense.

Bernard (1952) reported a queen from Guinea labelled "Nimba, Lamotte" may have been of the species "Monomorium explorator", somewhat uncertainly synonymised with Mono. leopoldinum by Bolton (1987, p 397), both being species of central and eastern Africa. As queens of explorator and leopoldinum otherwise have never been found and Bolton seems not to have seen the Bernard specimen, I do no more than note it here.

I felt previously that the synonymy of former Syllophopsis species was a little puzzling, as the forms labelled as "Syllophopsis" and which I had drawn from the CRIN material do not have an obviously bicarinate clypeus. Despite studying the comprehensive revision by Bolton (1987), I was not fully satisfied with my assignation of definitive names to the two former Syllophopsis nor to the former Diplomorium lujae. Now (2004) I have placed the first two with the destructor-group, feeling they probably fall into the crudely defined and over-embracing "Monomorium oscaris".

Those listed in the earlier papers by code names and numbers can be found on Monomorium species unidentifiable.

Contents MYRMICINAE Introduction
2007, 2012, 2015 - Brian Taylor CBiol FSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.