Monomorium rhopalocerum

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

Monomorium rhopalocerum casent0904594 p 1 high.jpg

Monomorium rhopalocerum casent0904594 d 1 high.jpg

Specimen Labels

Synonyms

One collection was made from a garden, and this is the only information known about the biology of this species.

Identification

Bolton (1987) - A member of the M. rhopalocerum complex in the M. monomorium species group. M. rhopalocerum is closely related to Monomorium exchao (=Monomorium termitobium), Monomorium binatu (=Monomorium termitobium) and Monomorium symmotu; and more distantly to Monomorium tablense. Of these five binatu (termitobium) has relatively long scapes (SI 100-105) which reach back to the occipital margin. Both binatu (termitobium) and tablense contrast with the remainder as their petiole nodes are relatively high and narrow as opposed to the broader lower nodes seen in the other three. M. rhopalocerum is larger than exchao (termitobium) and symmotu, and has a relatively broader head, but relative size of eyes and length of scapes fall into the same range in all three , though the scapes of rhopalocerum average a fractionally lower SI.

rhopalocerum - HW 0.42-0.50, CI 79-83, SL 0.36-0.44, SI 83-90, Diameter of eye 0.18-0.21 x HW.

symmotu - HW 0.36-0.39, CI 74-76, SL 0.34-0.35, SI 89-94, Diameter of eye 0.20-0.23 x HW.

exchao (termitobium) - HW 0.37-0.38, CI 74-76, SL 0.34, SI 89-91, Diameter of eye 0.20-0.21 x HW.

Apart from the dimensions symmotu differs from rhopalocerum by having the propodeal outline more evenly convex and more strongly convex immediately behind the metanotal groove. In exchao (termitobium) the propodeum behind the groove is more strongly raised in profile and passes through a much narrower curve into its posterior slope towards the declivity.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -33.81666667° to -34.33333°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

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

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.
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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.
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Biology

Castes

Queen

Images from AntWeb

Monomorium rhopalocerum casent0904591 h 1 high.jpgMonomorium rhopalocerum casent0904591 p 1 high.jpgMonomorium rhopalocerum casent0904591 d 1 high.jpgMonomorium rhopalocerum casent0904591 l 1 high.jpg
Syntype of Monomorium minutum hottentotaQueen (alate/dealate). Specimen code casent0904591. Photographer Will Ericson, uploaded by California Academy of Sciences. Owned by MSNG, Genoa, Italy.

Nomenclature

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

  • rhopalocerum. Monomorium rhopalocerum Emery, 1895h: 25, pl. 2, fig 29 (w.) SOUTH AFRICA.
    • Type-material: syntype workers (number not stated).
    • Type-locality: South Africa: Cape Town, 1893 (E. Simon).
    • Type-depository: MSNG.
    • Status as species: Arnold, 1916: 215; Emery, 1922e: 173; Wheeler, W.M. 1922a: 867; Ettershank, 1966: 91; Bolton, 1987: 407 (redescription); Bolton, 1995b: 266.
    • Senior synonym of hottentota: Bolton, 1987: 407; Bolton, 1995b: 266.
    • Senior synonym of leimbachi: Bolton, 1987: 407; Bolton, 1995b: 266.
    • Distribution: South Africa.
  • hottentota. Monomorium minutum subsp. hottentota Emery, 1895h: 26 (q.) SOUTH AFRICA.
    • Type-material: 2 syntype queens.
    • Type-locality: South Africa: Cape Town, 1893 (E. Simon).
    • Type-depository: MSNG.
    • Subspecies of minutum: Arnold, 1916: 218; Wheeler, W.M. 1922a: 864; Emery, 1922e: 172; Ettershank, 1966: 89.
    • Junior synonym of rhopalocerum: Bolton, 1987: 407; Bolton, 1995b: 262.
  • leimbachi. Monomorium leimbachi Forel, 1914d: 246 (w.) SOUTH AFRICA.
    • Type-material: syntype workers (number not stated).
    • Type-locality: South Africa: Cape Town, 1913, no. 336 (G. Arnold).
    • Type-depository: MHNG (possibly also in SAMC).
    • [Note: in the original description Forel records that specimens are from “coll. du Musée sudafricain”.]
    • Status as species: Arnold, 1916: 233; Emery, 1922e: 172; Wheeler, W.M. 1922a: 863; Ettershank, 1966: 90.
    • Junior synonym of rhopalocerum: Bolton, 1987: 407; Bolton, 1995b: 263.

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

Bolton (1987) - Monomorium hottentota is given as a provisional synonym. This is because the type-series of rhopalocerum is based on workers and that of hottentota on females. I have not seen any samples which contain both females and workers but the overall marked similarity between these two short series, and the fact that both show the same data, leads me to suspect that they originated in a single series that was somehow later split up.

Description

Worker

Bolton (1987) - TL 2.0-2.2, HL 0.53-0.60, HW 0.42-0.50, CI 79-83, SL 0.36-0.44, SI 83-90, PW 0.26-0.30, AL 0.55-0.60 (15 measured).

Anterior margin of prominent median portion of clypeus transverse to shallowly concave, rounding into the lateral margin; the two margins not separated by acute angles or projecting triangular denticles. Clypeal carinae narrow but sharply developed, the space between them extremely shallowly transversely concave. Clypeal carinae relatively close together posteriorly and subparallel, feebly diverging anteriorly. Eyes relatively small, their maximum diameter 0.18-0.21 x HW and with 6-7 ommatidia in the longest row. In full-face view the eyes conspicuously in front of the midlength of the sides of the head. Antennal scapes, when laid straight back from their insertions, failing to reach the occipital margin. Sides of head behind eyes approximately parallel, only extremely weakly convex and feebly convergent posteriorly. Occipital margin broad and usually very weakly and shallowly concave, at least medially. Promesonotal dorsum evenly broadly and shallowly convex in profile, sloping posteriorly to the broadly impressed metanotal groove. Metanotal cross-ribs relatively long and strong, conspicuous. Propodeal dorsum sloping posteriorly, rounding broadly and evenly into the declivity. Propodeal spiracle small. Subpetiolar process a narrow inconspicuous rim. Node of petiole in profile low and broad, broadly rounded above. Postpetiole much smaller than petiole, lower and its dorsal and anterior surfaces forming a single convexity. All dorsal surfaces of head and body with standing hairs, the promesonotum with 4-5 pairs. Mesopleuron shagreenate to finely reticulate in larger workers, partly smooth in small individuals. Sculpture otherwise absent except for scattered hair-pits and the conspicuous metanotal cross-ribs. Colour dull yellow, the gaster sometimes with a brownish tint.

Type Material

Bolton (1987) - Syntype workers, South Africa: Cape Town (E. Simon) (Museo Civico di Storia Naturale, Genoa) [examined].

References

References based on Global Ant Biodiversity Informatics

  • Addison P., and M. J. Samways. 2000. A survey of ants (Hymenoptera: Formicidae) that forage in vineyards in the Western Cape Province, South Africa
  • Arnold G. 1916. A monograph of the Formicidae of South Africa. Part II. Ponerinae, Dorylinae. Annals of the South African Museum. 14: 159-270.
  • Bolton B. 1987. A review of the Solenopsis genus-group and revision of Afrotropical Monomorium Mayr (Hymenoptera: Formicidae). Bulletin of the British Museum (Natural History). Entomology 54: 263-452.
  • Emery C. 1895. Voyage de M. E. Simon dans l'Afrique australe (janvier-avril 1893). 3e mémoire. Formicides. Annales de la Société Entomologique de France 64: 15-56.
  • Ettershank G. 1966. A generic revision of the world Myrmicinae related to Solenopsis and Pheidologeton (Hymenoptera: Formicidae). Aust. J. Zool. 14: 73-171.
  • Forel A. 1914. Formicides d'Afrique et d'Amérique nouveaux ou peu connus. Bulletin de la Société Vaudoise des Sciences Naturelles 50: 211-288.
  • Wheeler W. M. 1922. 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. Bulletin of the American Museum of Natural History 45: 711-1004