Royidris depilosa

AntWiki: The Ants --- Online
Royidris depilosa
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Royidris
Species group: admixta
Species: R. depilosa
Binomial name
Royidris depilosa
Bolton & Fisher, 2014

Royidris depilosa casent0020786 p 1 high.jpg

Royidris depilosa casent0020786 d 1 high.jpg

Specimen Labels

Found in litter samples and pitfall traps in tropical dry forest, spiny forest, and gallery forest.


A member of the admixta species group. Bolton and Fisher (2014) - R. depilosa shares a species group with Royidris admixta. The two appear closely related and are principally separated from the remainder of the genus by the relatively unspecialised nature of the mesosoma in both species, as discussed under the species group diagnoses. However, admixta is much more densely sculptured, and more densely pilose, species than depilosa.

Keys including this Species


Endemic to Madagascar.

Latitudinal Distribution Pattern

Latitudinal Range: -24.1° to -24.1°.

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.



Known only from the worker caste.


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

  • depilosa. Royidris depilosa Bolton & Fisher, 2014: 49, figs. 45-47 (w.) MADAGASCAR.
    • Type-material: holotype worker, 7 paratype workers.
    • Type-locality: Madagascar: Prov. Toliara, P.N. Tsimanampetsotsa, 6.7 km. 130° SE Efoetse, 25 m., 24°06’S, 43°46’E, 18-22.ii.2002, BLF 6160(40), CASENT0020786 (holotype), sifted litter, spiny forest thicket (B.L. Fisher et al); paratypes with same data (all BLF 6160).
    • Type-depositories: CASC (holotype); BMNH, CASC (paratypes).
    • Distribution: Madagascar.

Type Material

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



(holotype in parentheses). TL 1.9–2.3 (2.1), HL 0.50–0.58 (0.54), HW 0.39–0.46 (0.43), CI 77–81 (80), SL 0.36–0.42 (0.40), SI 90–95 (93), PW 0.28–0.34 (0.30), WL 0.55–0.68 (0.64) (12 measured).

Antennal club 3-segmented. Scapes short (SI < 100), when laid straight back in full-face view the apex of the scape just fails to reach the posterior margin of the head. With head in full-face view the eyes in front of the midlength of the side of the head capsule. EL 0.09–0.12 (EL/HW 0.23–0.26). Entire dorsum of head with scattered minute pits on a smooth and polished background; here and there vestigial traces (almost entirely effaced) of superficial reticulation may be visible. Promesonotum in profile not swollen or domed, the dorsum shallowly convex to the weakly impressed metanotal groove. Propodeal dorsum more or less flat to shallowly convex and slopes posteriorly, the dorsal line of the propodeum approximately follows that of the promesonotum; the propodeum is not strongly depressed below the level of the promesonotum. Pronotum without setae at the humeral angles; entire dorsum of mesosoma lacks setae. Dorsum of promesonotum smooth and shining, with widely scattered minute punctulae. Mesonotum smooth to superficially microreticulate; propodeal dorsum more strongly sculptured but even here the sculpture weak and superficial. Side of propodeum weakly microreticulate to reticulate-punctulate; mesopleuron finely reticulate-punctulate and the sculpture usually extends onto the side of the pronotum, at least posteriorly. Metafemur relatively short, MfL 0.35–0.42 (MfL/HW 0.90–0.95, MfL/MfH 3.00–3.64). Petiole without setae on the posterior face of the node; postpetiole usually with a pair of setae present posteriorly; first gastral tergite with setae restricted to the extreme posterior margin. Postpetiole relatively broad in dorsal view, maximum width 0.17–0.21 (0.44–0.48 × HW). Colour dull yellow to yellowish brown; gaster may be somewhat darker.


  • Bolton, B. & Fisher, B.L. 2014. The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n. Zootaxa 3791:1–99. doi:10.11646/zootaxa.3791.1.1

References based on Global Ant Biodiversity Informatics

  • Bolton B., and B. L. Fisher. 2014. The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n. Zootaxa 3791(1): 1-99.