Messor capensis

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Messor capensis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Stenammini
Genus: Messor
Species: M. capensis
Binomial name
Messor capensis
(Mayr, 1862)

Messor capensis casent0217867 p 1 high.jpg

Messor capensis casent0217867 d 1 high.jpg

Specimen Labels

Synonyms

Identification

The taxa capensis, Messor decipiens and Messor piceus, treated here as separate species, may in fact represent only a single variable species. The differences invoked to distinguish the three are minor (see key) and may eventually prove to be gradient. Among the species in which the first gastral tergite is uniformly hairy the three taxa mentioned above are characterized together by their relatively small eyes, lack of strong gastral sculpture, relatively straight-sided head and short propodeum, and lack of a median prominence on the posterior half of the clypeus. (Bolton 1982)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Botswana, Namibia, South Africa (type locality), Zimbabwe.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

As is common in this genus, workers forage for seeds that are retrieved to the nests. In the Western Cape of South Africa, M. capensis gather seeds of many species, including rooibos (Aspalathus linearis) even though these lack arils. Seeds remain viable after years underground and can survive episodic fire.

Rooibos 'tea' offers several health benefits (rich in antioxidants; caffeine-free; low tannin). Seeds are tiny and housed in small pods. When each pod is ripe, it will burst open, scattering the seeds on the sandy ground. Moreover the pods on a particular bush reach maturity at different rates, so it is difficult to obtain large quantities of rooibos seeds by sifting. Indigenous knowledge (Khoi or San) about the banks of rooibos seeds in M. capensis nests allowed the start of commercial plantations. Nowadays some Cederberg farmers continue to dig up the ants' granaries every few years.

(written by Christian Peeters based on interviews with local farmer Bennie Bezuidenhout, internet information, and Lawrence Green's (1949) book In The Land Of Afternoon. Standard Press Ltd. pp. 52 to 54)


Rooibos plantation in the Nardouwsberg (Western Cape). Messor capensis gather the seeds and stock them in their underground nests. Photo by Christian Peeters.

Castes

Worker

Nomenclature

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

  • capensis. Atta capensis Mayr, 1862: 743 (w.) SOUTH AFRICA. Mayr, 1866b: 896 (q.m.). Combination in Aphaenogaster: Roger, 1863b: 30; in Stenamma (Messor): Emery, 1895h: 35; in Messor: Forel, 1910e: 444. Subspecies of barbarus: Emery, 1891b: 12; Forel, 1910e: 444; Arnold, 1920a: 405; Emery, 1922c: 98; Stitz, 1923: 150; Prins, 1963: 100. Status as species: Santschi, 1917e: 94; Wheeler, W.M. 1922a: 804; Bolton, 1982: 345. Senior synonym of braunsi, donisthorpei, pseudoaegyptiaca, schencki: Bolton, 1982: 345.
  • pseudoaegyptiaca. Aphaenogaster pseudoaegyptiaca Emery, 1884a: 384 (w.) SOUTH AFRICA. Arnold, 1920a: 409 (q.m.). Combination in Stenamma (Messor): Emery, 1895h: 35; in Messor: Santschi, 1917e: 94. Subspecies of capensis: Santschi, 1917e: 94. Junior synonym of capensis: Bolton, 1982: 345.
  • braunsi. Messor braunsi Forel, 1913a: 138 (w.) SOUTH AFRICA. Stitz, 1923: 149 (q.). Junior synonym of capensis: Bolton, 1982: 345.
  • schencki. Messor capensis var. schencki Wheeler, W.M. 1922a: 805 (w.) NAMIBIA. [First available use of Messor barbarus subsp. capensis var. schencki Forel, 1910f: 15; unavailable name.] Junior synonym of capensis: Bolton, 1982: 345.
  • donisthorpei. Messor donisthorpei Santschi, 1937a: 51 (w.q.) NAMIBIA. Junior synonym of capensis: Bolton, 1982: 345.

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

Description

Worker

Bolton (1982) - Medium to large, HW 2.35 -> 3.40.

Anterior clypeal margin varying from shallowly convex to transverse, only very rarely with the faintest vestige of a median indentation. With the head in full face view the sides more or less straight and approximately parallel, never evenly convex nor obviously diverging anteriorly. Occipital margin broadly and shallowly concave to indented medially. In HW range 2.35-3.44 the maximum diameter of the eye is 0.40-0.58, about 0.15-0.19 x HW, and the CI range is 103-119. Propodeum in profile with the dorsum rounding narrowly into the declivity in most cases; in some more broadly rounded and in a few right-angled, but only rarely with dentiform prominences and here usually only in the largest workers. Usual sculpture of entire dorsum of head of fine, densely packed parallel longitudinal rugulae, most commonly with fine punctulation between them. Variation in the sculpture consists of a reduction, in density or intensity, or one or both of these components. Sometimes the rugulae are more widely spaced and fainter than is usual, in which case the punctulate ground-sculpture is much more obvious and may appear as the dominant component in places. On the other hand the punctulate sculpture may fade out, leaving the rugulae sharply defined; the rugulae may then also become less intense and leave the head only feebly sculptured. Dorsal alitrunk usually rugose or rugulose everywhere but, as on the head, this sculpture may be reduced until it is very faint or even absent. When distinctly present the direction of sculpture on the pronotum shows variation. Commonly it is longitudinal but forms with the sculpture diagonal, transverse, irregular or varying on different parts of the surface are fairly frequent. First gastral tergite unsculptured or at most with a very faint superficial patterning. All dorsal surfaces of head and body with numerous conspicuous standing hairs. Colour black to dark reddish brown, the head and alitrunk always the same colour, the gaster sometimes darker.

References

  • Arnold, G. 1920a. A monograph of the Formicidae of South Africa. Part IV. Myrmicinae. Ann. S. Afr. Mus. 14: 403-578 (page 405, Subspecies/race of barbarus)
  • Bolton, B. 1982. Afrotropical species of the myrmecine ant genera Cardiocondyla, Leptothorax, Melissotarsus, Messor and Cataulacus (Formicidae). Bulletin of the British Museum (Natural History). Entomology, 46: 307-370 (page 345, Status as species,Senior synonym of braunsi, donisthorpei, pseudoaegyptiaca and schencki)
  • Emery, C. 1891c. Exploration scientifique de la Tunisie. Zoologie. - Hyménoptères. Révision critique des fourmis de la Tunisie. Paris: Imprimerie Nationale, iii + 21 pp. (page 12, Subspecies/race of barbarus)
  • 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 35, Combination in Stenamma (Messor))
  • Emery, C. 1922c. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [part]. Genera Insectorum 174B: 95-206 (page 98, Subspecies/race of barbarus)
  • Forel, A. 1910f. Note sur quelques fourmis d'Afrique. Ann. Soc. Entomol. Belg. 54: 421-458 (page 444, Combination in Messor Subspecies/race of barbarus)
  • Mayr, G. 1862. Myrmecologische Studien. Verh. K-K. Zool.-Bot. Ges. Wien 12: 649-776 (page 743, worker described)
  • Mayr, G. 1866b. Diagnosen neuer und wenig gekannter Formiciden. Verh. K-K. Zool.-Bot. Ges. Wien 16: 885-908 (page 896, queen, male described)
  • Prins, A. J. 1963. A list of the ants collected in the Kruger National Park with notes on their distribution. Koedoe 6: 91-108 (page 100, Subspecies/race of barbarus)
  • Roger, J. 1863b. Verzeichniss der Formiciden-Gattungen und Arten. Berl. Entomol. Z. 7(B Beilage: 1-65 (page 30, Combination in Aphaenogaster)
  • Santschi, F. 1917e. Races et variétés nouvelles du Messor barbarus L. Bull. Soc. Hist. Nat. Afr. Nord 8: 89-94 (page 94, Status as species)
  • Stitz, H. 1923. Hymenoptera, VII. Formicidae. Beitr. Kennt. Land- Süsswasserfauna Dtsch.-Südwestafr. 2: 143-167 (page 150, Subspecies/race of barbarus)
  • 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 804, Status as species)