Monomorium anceps

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Monomorium anceps
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Solenopsidini
Genus: Monomorium
Species: M. anceps
Binomial name
Monomorium anceps
Emery, 1895

Monomorium anceps casent0235921 p 1 high.jpg

Monomorium anceps casent0235921 d 1 high.jpg

Specimen Labels

Identification

Bolton (1987):

As the three names australe, anceps and termitarium constitute a very close triad which may represent only one real species, the usual format of the revision is abandoned here so that the three may be considered together.

These three southern African forms are retained for the present as separate species until more material is collected for study, at which time it may be possible to show whether they are indeed separate or whether two or all of them are synonymous. All three are represented only by short syntypic series at the time of writing. The three together are characterized by the following snared characters within the salomonis group.

Relatively small forms, their combined dimensions being TL 2.4-2.6, HL 0.60-0.66, HW 0.46-0.52, CI 75-79, SL 0.47-0.54, SI 100-104, PW 0.30-0.35, AL 0.68.0-76. Maximum diameter of eye 0.24-0.26 x HW and with 7-9 ommatidia in the longest row. [Note that this combined range of dimensions is no greater than those frequently encountered in what are indubitably single species elsewhere in this species-group.]

Head with feebly developed shagreenate-granular sculpture so that the cephalic dorsum appears weakly shining and semi-smooth. Dorsal alitrunk lacking standing hairs of any description. Petiole with a single pair of backward directed hairs, postpetiole with 1-2 pairs of hairs. First gastral tergite with 2-3 pairs of hairs in front of the apical transverse row, the hairs confined to the basal half of the sclerite.

Within the limits of this diagnosis the dimensions of the three are as follows.

M. termitarium syntypes, TL 2.5-2.6, HL 0.60-0.64, HW 0.46-0.51 , CI 75-79, SL 0.48-0.53, SI 100-104, PW 0.30-0.35, AL 0.70-0.76; maximum diameter of eye 0.24-0.25 x HW, with 7-8 ommatidia in the longest row (6 measured).

M. australe syntypes, TL 2.5-2.6, HL 0.64-0.66, HW 0.50-0.52, CI 78-79, SL 0.50-0.54, SI 100-104, PW 0.32-0.34, AL 0.74-0.76; maximum diameter of eye 0.25-0.26 x HW, with 9 ommatidia in the longest row (4 measured).

M. anceps syntypes, TL 2.4, HL 0.60, HW 0.47, CI 78, SL 0.47, SI 100, PW 0.30, AL 0.68; maximum diameter of eye 0.26 x HW, with 7-8 ommatidia in the longest row (2 measured).

Characters which presently serve to isolate the three syntypic series include colour, sculpture and gastral pilosity, but all are weak and may prove to be gradient. For the present the differentiation is as follows.

M. termitarium is a uniformly yellow species from Botswana in which the mesonotal dorsum is superficially reticulate-punctate. The pronotal dorsum is similarly sculptured but the sculpture is more reduced and somewhat effaced so that the punctures are vestigial. In other words the pronotal dorsal sculpture is obviously a reduced and effaced version of that seen on the mesonotum. Two pairs of hairs are present on the basal half of the first gastral tergite.

M. australe, from Cape Province, South Africa, is a medium brown species with a darker brown gaster. Dorsal alitrunk sculpture corresponds with the above, being reticulate-punctate on the mesonotum and feebly reticulate on the pronotum, again the pronotal sculpture obviously a reduced and effaced version ofthe mesonotal. The syntypes show varying degrees of abrasion but it appears that two pairs of hairs occur on the basal half of the first gastral tergite.

M. anceps, from Transvaal, South Africa, is medium brown with a darker brown gaster. The mesonotal dorsum is sharply reticulate-punctate whilst the pronotal dorsum is finely shagreenate. In other words the two areas show distinctly contrasting sculpture and the pronotal component does not appear to be merely a reduced and effaced version of that seen on the mesonotum. Three pairs of hairs occur on the basal half of the first gastral tergite.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: South Africa (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.

  • anceps. Monomorium subopacum var. anceps Emery, 1895h: 24 (w.) SOUTH AFRICA. Combination in M. (Xeromyrmex): Wheeler, W.M. 1922a: 872. Raised to species: Bolton, 1987: 336.

Description

References

  • Bolton, B. 1987. A review of the Solenopsis genus-group and revision of Afrotropical Monomorium Mayr (Hymenoptera: Formicidae). Bull. Br. Mus. (Nat. Hist.) Entomol. 54: 263-452 (page 336, Raised to species)
  • Emery, C. 1895i. Voyage de M. E. Simon dans l'Afrique australe (janvier-avril 1893). 3e mémoire. Formicides. Ann. Soc. Entomol. Fr. 64: 15-56 (page 24, worker described)
  • Wheeler, W. M. 1922j. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bull. Am. Mus. Nat. Hist. 45: 711-1004 (page 872, Combination in M. (Xeromyrmex))