Strumigenys olsoni

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Strumigenys olsoni
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. olsoni
Binomial name
Strumigenys olsoni
(Bolton, 2000)

Pyramica olsoni casent0005455 profile 1.jpg

Pyramica olsoni casent0005455 dorsal 1.jpg

Specimen labels

Widely ranging across Madagascar, S. olsoni occurs in habitats that vary from grassland to rainforest. Most collections are from litter-samples, one is noted as being from a rotten stump.


The only member of the Strumigenys olsoni-group.

Keys including this Species


Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb






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

  • olsoni. Pyramica olsoni Bolton, 2000: 353, figs. 223, 243 (w.q.) MADAGASCAR. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 125

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



Holotype. TL 2.3, HL 0.59, HW 0.42, CI 71, ML 0.11, MI 19, SL 0.24, SI 57, PW 0.25, AL 0.57. Dorsum of head with minute appressed hairs, in profile the vertex also with a few short erect simple hairs between the highest point and the occipital margin. Dorsolateral margin of head in full-face view with two short simple projecting hairs, the first the apicoscrobal and the second on the side of the occipital lobe. Upper scrobe margins more or less straight in full-face view, feebly divergent posteriorly and confluent with the sides of the occipital lobes; the latter strongly projecting posteriorly and with narrowly rounded posterior lobes. In profile the occipital lobe is narrow and projects strongly backwards. Clypeus and vertex polished, with minute, widely scattered small punctures that do not detract from the overall glossy appearance of the head. Eye with 5 ommatidia in its greatest diameter. Alitrunk and waist segments completely lacking sculpture, the first gastral tergite un sculptured except for the basigastral costulae that arise in two clusters, one on each side of a smooth median area. Dorsa of promesonotum, waist segments and first gastral tergite with numerous simple hairs that are erect or suberect. Pronotum evenly transversely convex, the dorsum in profile also convex. Petiole node in dorsal view slightly longer than broad , in profile the node with a free sloping posterior face. Disc of postpetiole twice broader than long in dorsal view, its anterior margin broadly shallowly concave, the sides shallowly convex and strongly convergent posteriorly.

In profile the postpetiole extremely narrow dorsoventrally, the sternite very reduced. Spongiform appendages of waist segments thin and lamelliform. Lateral appendages of petiole node in dorsal view a pair of thin, flap-like lobes, anterior collar of postpetiole a thin lamella. Ventral curtain of petiole in profile massive, as deep as the node is high. Lateral lobe of postpetiole a continuous flange, broadest posteriorly; ventral lobe small.

Paratypes. TL 2.2-2.3, HL 0.58-0.60, HW 0.42-0.44, CI 71-73, ML 0.10-0.11, MI 17-19, SL 0.23-0.25, SI 55-60, PW 0.24-0.26, AL 0.55-0.58 (6 measured).

Type Material

Holotype worker, Madagascar: 48 km. ENE Morondava, 20004'S, 44°39'E, 30 m., 5.i.1991, tropical dry forest (D.M. Olson) (The Natural History Museum).

Paratypes. 14 workers and 2 queens (dealate), with same data as holotype; 3 workers with same data but each dated 4-6.i.1991 on an upper label, and 4.i.1991 on a lower label; 5 workers with same data but 7.i.1991 (BMNH, University of California, Davis, Museum of Comparative Zoology).


  • Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99: 1-191.
  • Bolton, B. 2000. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028 (page 353, worker described)

References based on Global Ant Biodiversity Informatics

  • Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
  • 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.
  • Fisher, B. 2002. Ant diversity patterns along an elevational gradient in the Reserve Speciale de Manongarivo, Madagascar. in Gautier, L. and S.M. Goodman, editors, Inventaire Florestique et Faunistique de la Reserve Speciale de Manongarivo (NW Madagascar)
  • Goodman S., Y. Anbdou, Y. Andriamiarantsoa, B. L. Fisher, O. Griffiths, B. Keitt, J. J. Rafanomezantsoa, E. Rajoelison, J. C. Rakotonirina, L. Ranaivoarisoa et al. 2017. Results of a biological inventory of the Nosy Ankao island group, Parc National de Loky-Manambato, northeastern Madagascar. Malagasy Nature, Association Vahatra, 2017, 11, <>