Tetramorium olana

AntWiki: The Ants --- Online
Tetramorium olana
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Tetramorium
Species: T. olana
Binomial name
Tetramorium olana
Hita Garcia & Fisher, 2012

Tetramorium olana casent0044365 p 1 high.jpg

Tetramorium olana casent0044365 d 1 high.jpg

Specimen Labels

Only known from three localities in the north and northwest of Madagascar: Manongarivo, Ampasindava, and Andavakoera. All three are rainforests situated at elevations between 400 to 600 m. The available collection data suggests that T. olana lives or forages in leaf litter or lower vegetation. (Hita Garcia and Fisher 2012)


A member of the Tetramorium bonibony-species group

Tetramorium olana is distinguishable from the remainder of the species group by the following character combination: mesosoma with well-developed anterior face of pronotum, but without distinct anterodorsal median protuberance; petiolar node cuneiform and not strongly anteroposteriorly compressed dorsally (LPeI 45 - 50; DPeI 183 - 200); body of uniformly yellow to light brown colour. (Hita Garcia and Fisher 2012)

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: -13.1183° to -13.96167°.

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

Tetramorium olana casent0044402 d 1 high.jpgTetramorium olana casent0044402 h 1 high.jpgTetramorium olana casent0044402 p 1 high.jpgTetramorium olana casent0044402 l 1 high.jpg
Worker. Specimen code casent0044402. Photographer Estella Ortega, uploaded by California Academy of Sciences. Owned by CAS, San Francisco, CA, USA.
Tetramorium olana casent0044484 p 1 high.jpgTetramorium olana casent0044484 h 1 high.jpgTetramorium olana casent0044484 d 1 high.jpgTetramorium olana casent0044484 l 1 high.jpg
Worker. Specimen code casent0044484. Photographer Estella Ortega, uploaded by California Academy of Sciences. Owned by CAS, San Francisco, CA, USA.
Tetramorium olana casent0044485 h 1 high.jpgTetramorium olana casent0044485 p 1 high.jpgTetramorium olana casent0044485 d 1 high.jpgTetramorium olana casent0044485 l 1 high.jpg
Holotype of Tetramorium olanaWorker. Specimen code casent0044485. Photographer Will Ericson, uploaded by California Academy of Sciences. Owned by CAS, San Francisco, CA, USA.


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

  • olana. Tetramorium olana Hita Garcia & Fisher, 2012: 41, figs. 43, 54-56 (w.) MADAGASCAR.

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



HL 0.56 - 0.65 (0.62); HW 0.54 - 0.63 (0.61); SL 0.39 - 0.45 (0.43); EL 0.12 - 0.15 (0.14); PH 0.33 - 0.36 (0.34); PW 0.38 - 0.46 (0.43); WL 0.71 - 0.82 (0.77); PSL 0.21 - 0.23 (0.22); PTL 0.10 - 0.13 (0.11); PTH 0.22 - 0.26 (0.24); PTW 0.19 - 0.24 (0.22); PPL 0.17 - 0.23 (0.21); PPH 0.22 - 0.27 (0.25); PPW 0.21 - 0.26 (0.24); CI 96 - 100 (98); SI 69 - 73 (70); OI 22 - 24 (23); DMI 54 - 58 (56); LMI 43 - 46 (44); PSLI 33 - 37 (35); PeNI 49 - 52 (51); LPeI 45 - 50 (47); DPeI 183 - 200 (192); PpNI 54 - 56 (56); LPpI 77 - 88 (83); DPpI 111 - 124 (115); PPI 106 - 115 (109) (11 measured).

Head weakly longer than wide to as long as wide (CI 96 - 100). Anterior clypeal margin with median impression. Frontal carinae weakly to moderately developed, fading out between posterior eye margin and posterior head margin. Antennal scrobes absent. Antennal scapes short, not reaching posterior head margin (SI 69 - 73). Eyes of moderate size (OI 22 - 24). Mesosoma with well-developed anterior face but without distinct anterodorsal median protuberance on pronotum, margination from lateral to dorsal mesosoma weak to moderate; promesonotal suture and metanotal groove absent; mesosoma comparatively high, compact, and stout (LMI 43 - 46). Propodeal spines long to very long, spinose, and acute (PSLI 33 - 37); propodeal lobes small and triangular. Petiolar node in profile cuneiform, weakly anteroposteriorly compressed dorsally, approximately 2 to 2.2 times higher than long (LPeI 45 - 50), anterior and posterior faces not parallel, anterodorsal margin situated higher than posterodorsal, dorsum moderately tapering backwards posteriorly; node in dorsal view between 1.8 to 2 times wider than long (DPeI 183 - 200). Postpetiole in profile approximately rounded, approximately 1.1 to 1.3 times higher than long (LPpI 77 - 88), in dorsal view approximately 1.1 to 1.3 times wider than long (DPpI 111 - 124). Postpetiole in profile appearing somewhat more voluminous than petiolar node, in dorsal view weakly wider than petiolar node (PPI 106 - 115). Mandibles striate; clypeus with distinct median longitudinal ruga and one or two weaker and often shorter rugae laterally; cephalic dorsum between frontal carinae with five to nine longitudinal rugae, rugae ending at posterior head margin but often broken or with cross-meshes, close to posterior head margin reticulate-rugose, always with one well-developed longitudinal median ruga, median ruga running from posterior head margin to posterior clypeal margin, approximately at eye level diverging into two rugae leading to posterior clypeal margin; lateral and ventral head mainly reticulate-rugose to longitudinally rugose. Ground sculpture on head weakly to moderately developed. Mesosoma anterodorsally strongly reticulate-rugose, posteriorly and laterally reticulate-rugose to irregularly longitudinally rugose. Waist segments and gaster unsculptured, smooth, and shiny. All dorsal surfaces of body with abundant, long, fine, and erect pilosity. Body of uniform yellow to light brown colour.

Type Material

Holotype worker, MADAGASCAR, Antsiranana, Forêt d' Andavakoera, 21.4 km 75° ENE Ambilobe, 4.6 km 356° N Betsiaka, 13.1183 S, 49.23 E, 425 m, rainforest, sifted litter (leaf mold, rotten wood), collection code BLF10260, 15.XII.2003 (B.L. Fisher) (California Academy of Sciences: CASENT0044485). Paratypes, 12 workers with same data as holotype (The Natural History Museum: CASENT0044353; CASC: CASENT0044342; CASENT0044359; CASENT0044381; CASENT0044399; CASENT0044402; CASENT0044407; CASENT0044477; CASENT0044484; CASENT0044503; Musee d'Histoire Naturelle Genève: CASENT0044458).


The name of the new species is Malagasy and means "problem". It refers to the initially difficult species delimitation of T. olana. The species epithet is a noun in apposition and thus invariant.


References based on Global Ant Biodiversity Informatics

  • Garcia H. F. and B. L. Fisher. 2012. The ant genus Tetramorium Mayr (Hymenoptera: Formicidae) in the Malagasy region—taxonomy of the T. bessonii, T. bonibony, T. dysalum, T. marginatum, T. tsingy, and T. weitzeckeri species groups. Zootaxa 3365: 1-123