Nesomyrmex retusispinosus

AntWiki: The Ants --- Online
Nesomyrmex retusispinosus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Nesomyrmex
Species group: sikorai
Species: N. retusispinosus
Binomial name
Nesomyrmex retusispinosus
(Forel, 1892)

Nesomyrmex retusispinosus casent0060902 profile 1.jpg

Nesomyrmex retusispinosus casent0060902 dorsal 1.jpg

Specimen labels

This species is known to occur in rain forests and montane forests in lowlands between 918 m and 1080 m in central Madagascar.


A member of the sikorai species-group.

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: -18.76087° to -21.51167°.

Tropical South

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (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

Nesomyrmex retusispinosus casent0101616 head 1.jpgNesomyrmex retusispinosus casent0101616 profile 1.jpgNesomyrmex retusispinosus casent0101616 dorsal 1.jpgNesomyrmex retusispinosus casent0101616 label 1.jpg
Worker. Specimen code casent0101616. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MHNG, Geneva, Switzerland.


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

  • retusispinosus. Leptothorax retusispinosus Forel, 1892l: 267 (w.) MADAGASCAR.
    • Combination in L. (Goniothorax): Emery, 1896g: 58 (footnote).
    • Combination in Nesomyrmex: Bolton, 2003: 272.
    • Status as species: Dalla Torre, 1893: 126; Wheeler, W.M. 1922a: 1030; Bolton, 1995b: 243; Csösz & Fisher, 2016b: 22 (redescription).

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



Csösz and Fisher (2016) - Body color: yellow; brown. Body color pattern: concolorous. Absolute cephalic size: 812 μm [731, 921]. Cephalic length vs. maximum width of head capsule (CL/CWb): 1.17 [1.07, 1.233]. Postocular distance vs. cephalic length (PoOc/CL): 0.483 [0.464, 0.498]. Postocular sides of cranium contour, anterior view orientation: converging posteriorly. Postocular sides of cranium contour, anterior view shape: convex. Vertex contour line in anterior view shape: straight; feebly convex. Vertex sculpture: main sculpture rugoso-reticulate, ground sculpture areolate. Gena contour line in anterior view shape: convex. Gena contour from anterior view orientation: strongly converging. Gena sculpture: rugoso-reticulate with areolate ground sculpture. Concentric carinae laterally surrounding antennal foramen: present. Eye length vs. absolute cephalic size (EL/CS): 0.237 [0.225, 0.251]. Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.294 [0.285, 0.302]. Longitudinal carinae on median region of frons: present. Smooth median region on frons: absent. Antennomere count: 12. Scape length vs. absolute cephalic size (SL/CS): 0.838 [0.812, 0.862]. Median clypeal notch: present. Median carina of clypeus: present or absent. Spine length vs. absolute cephalic size (SPST/CS): 0.43 [0.4, 0.459]. Minimum spine distance vs. absolute cephalic size (SPBA/CS): 0.24 [0.219, 0.259]. Apical spine distance vs. absolute cephalic size (SPTI/CS): 0.322 [0.293, 0.332]. Propodeal spine shape: slightly or strongly bent. Apical distance of pronotal spines vs. absolute cephalic size (PSTI/CS): 0.659 [0.621, 0.678]. Metanotal depression: present. Dorsal region of mesosoma sculpture: rugulose with areolate ground sculpture. Lateral region of pronotum sculpture: areolate ground sculpture, main sculpture rugoso-reticulate. Mesopleuron sculpture: areolate ground sculpture, superimposed by dispersed rugae. Metapleuron sculpture: areolate ground sculpture, superimposed by dispersed rugae. Petiole width vs. absolute cephalic size (PEW/CS): 0.24 [0.219, 0.262]. Dorsal region of petiole sculpture: ground sculpture areolate, main sculpture dispersed rugose. Postpetiole width vs. absolute cephalic size (PPW/CS): 0.39 [0.358, 0.415]. Dorsal region of postpetiole sculpture: ground sculpture areolate, main sculpture dispersed rugose.

Type Material

Csösz and Fisher (2016) - Holotype worker: “L. retusispinosus, type, Forel, For d'andrangoloaca [Antananarivo, -18.91 N, 47.55 E], Madagascar (Sikora)”, (Musee d'Histoire Naturelle Genève, CASENT0101616).


  • Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 272, Combination in Nesomyrmex)
  • Csösz, S. & Fisher, B.L. 2016b. Toward objective, morphology-based taxonomy: a case study on the Malagasy Nesomyrmex sikorae species group. PLoS ONE 11 (4): 31 pp. e0152454. doi: 10.1371/journal.pone.0152454.
  • Emery, C. 1896g. Studi sulle formiche della fauna neotropica. XVII-XXV. Bull. Soc. Entomol. Ital. 28: 33-107 (page 58, Combination in L. (Goniothorax))
  • Fisher, B. L. 1997a. Biogeography and ecology of the ant fauna of Madagascar (Hymenoptera: Formicidae). J. Nat. Hist. 31: 269-302 (see also)
  • Forel, A. 1892o. Les Formicides. [concl.]. In: Grandidier, A. Histoire physique, naturelle, et politique de Madagascar. Volume XX. Histoire naturelle des Hyménoptères. Deuxième partie. Supplèment au 28e fascicule. Paris: Hachette et Cie, pp. 229-280. (page 267, worker described)
  • Wheeler, W. M. 1922k. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. IX. A synonymic list of the ants of the Malagasy region. Bull. Am. Mus. Nat. Hist. 4 45: 1005-1055 (see also)

References based on Global Ant Biodiversity Informatics

  • Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.