Hylomyrma primavesi

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Hylomyrma primavesi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Pogonomyrmecini
Genus: Hylomyrma
Species: H. primavesi
Binomial name
Hylomyrma primavesi
Ulysséa, 2021

All specimens were collected with winkler extractors and pitfall traps at elevations between 1100 and 1400 m in areas of “Campos rupestres”. Those relatively high-elevation areas are characterized by savannas and grasslands, with plants and outcrops. Except for the presence of worker-like intercastes, there is no further information available regarding the biology of H. primavesi. The winged queen of this species is unknown, then perhaps the specimens determined here as intercastes are responsible for reproduction. (Ulyssea & Brandao, 2021)

Ulyssea et al. (2024) report that Hylomyrma primavesi forage solitarily and prefer very small insects (Collembola and larvae, pupae, and imagos of Diptera and Coleoptera). Its nests are found in sandy soil and are not deep. One straight tunnel connects the tube entrance to a final chamber. The colonies comprised approximately 7 - 65 workers and intercaste specimens and one ergatoid queen per colony. The structure of the female reproductive tract of H. primavesi is similar to that in other Myrmicinae. Workers and intercaste specimens have one pair of ovarioles and lack the spermatheca, while the ergatoid queen has three pairs of ovarioles and spermatheca. Most remarkably, it is the only Hylomyrma species that has only ergatoid queens.

At a Glance • Ergatoid queen  


Body black; regular striae on head dorsum diverge towards posterior margin; rugose striae on mesosoma and petiole; promesonotal junction and metanotal groove discernible by a slight depression (LV) and altered sculpture (VD); propodeal spine length similar to dorsal tooth of propodeal lobe; dorsal margin of petiole discontinuous; transverse striae on node ventral surface; profemur posterior surface smooth; striae on protibia extensor surface weakly marked; striation on tergum of first gastral segment restricted to base; thick branched setae flattened in its final half, with several branches.

Hylomyrma primavesi is unique among its congeners in its blackish body. Nonetheless, its body sculpture resembles that of Hylomyrma balzani. Hylomyrma primavesi can be distinguished from H. balzani (characteristic in parentheses) by the larger body, TL 5.32–5.78 mm, WL 1.34–1.48 mm (vs. smaller, TL 4.27–5.23 mm, WL 1.10–1.39 mm), the distinct promesonotal junction and metanotal groove (vs. both indistinct). Both species occur in Brazil, whereas H. primavesi is known only from higher elevations in Serra do Cipó, MG (Fig. 88), H. balzani has a broad distribution, occurring mainly in eastern portions of Brazil from north to south (Fig. 84).

Half of all specimens examined have a central ocellus (n=6) or a more or less pronounced depression on the region where winged queens present the central ocellus (n=11). Moreover, most of the specimens have the promesonotal junction and metanotal groove distinguishable by a slight depression or altered sculpture. This morphological variation is associated with intercastes at least in other Hylomyrma species with intercastes. Winged queens are not known in this species, thus these intercastes may perform reproduction. Specimens identified as workers do not present ocelli or ocellar depression, nor the conspicuous promesonotal junction and metanotal groove. One of the workers studied presents the laterals of the mesosoma flattened. This was interpreted as a deformity.

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: -19° to -19°.

Tropical South
  • Source: Ulysséa & Brandao, 2021

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (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.




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

  • primavesi. Hylomyrma primavesi Ulysséa, in Ulysséa & Brandão, 2021: 94, figs. 62, 80J, 88 (w.) BRAZIL (Minas Gerais).
    • Type-material: holotype worker, 5 paratype workers, 20 paratype worker-queen intercastes.
    • Type-locality: holotype Brazil: Minas Gerais, Santana do Riacho, Serra do Cipó, APA Morro da Pedreira, 1300 m., 19°17’50.11’’S, 43°35’39.69’’W, 16.i.2002, Q16-X-V-4 (T.C. Lana); paratypes: 1 worker, 1 intercaste with same data but iv.2011, Q16-X-VI-2, Q16-X-VI-4, 1 intercaste with same data but iv.2013, Q16-X-V-4, 2 intercastes with same data but 19°13’48.89’’S, 43°34’35.19’’W, 1100 m., x.2011, C11-X-I-2, C11-X-I-4, 1 worker, 2 intercastes PARNA Serrado do Cipó, 1400 m., 25-30.iv.2011, AP-X-III-1, -2, -3, 2 intercastes as last but vii.2011, AP-X-III-2, AP-X-II-3, 2 intercastes as last but x.2011, AP-X-III-4, 3 intercastes as last but i.2012, AP-X-III-1, -3, -4, 2 workers, 1 intercaste as last but iv.2012, AP-X-III-1, -2, -3, 1 worker, 1 intercaste as last but vii.2012, AP-X-III-2, -4, 1 intercaste as last but x.2012, AP-X-III-2, 3 intercastes as last but i.2013, AP-X-III-1, -2, -3, 1 intercaste as last but iv.2013, AP-X-III-3, 1 intercaste as last but vii.2013, AP-X-III-3.
    • Type-depositories: MZSP (holotype); CASC, DZUP, IAVH, JTLC, MCZC, MZSP, USNM (paratypes).
    • Distribution: Brazil.

Type Material

  • Holotype: BRAZIL: MG[Minas Gerais]: Santana do Riacho, Serra do Cipó, APA[Environmental Protection Area] Morro da Pedreira, 19°17′50.11″S, 43°35′39.69″W, 1300m, 16.i.2012, campo rupestre, pitfall-solo, T.C. Lana col., Q16-X-V-4[Area code - Xeric environment - Transect number - Point number] (1W) (MZSP67412) [MZSP].
  • Paratypes: same data as holotype except abril/2011, Q16-X-VI-2 (1W) (MZSP67413) [MZSP]; Q16-X-VI-4 (1I) (MZSP67414) [MZSP]; abril/2013, Q16-X-V-4 (1I) (MZSP67415) [MZSP]; 19°13′48.89″S, 43°34′35.19″W, 1100m, x.2011, C11-X-I-2 (1I) (MZSP67416) [MZSP]; C11-X-I-4 (1I) (MZSP) [MZSP 67417]; PARNA[National Park] Serra do Cipó, 19°15′49.92″S, 43°32′04.35″W, 1400m, 25-30.iv.2011, AP-X-III-1, pitfall-solo (1W covered with gold) (MZSP67418) [MZSP]; same except AP-X-III-2 (1I) (MZSP67419) [MZSP]; AP-X-III-3 (1I) (MZSP67420) [MZSP]; jul/2011, AP-X-III-2 (1I) (MZSP67421) [MZSP]; AP-X-II-3 (1I) (MZSP67422) [MZSP]; x.2011, AP-X-III-4 (2I) (MZSP67423, MZHY60) [MZSP]; i.2012, AP-X-III-1 (1I) (MZSP67424) [MZSP]; AP-X-III-3 (1I) (MZSP67425) [MZSP]; AP-X-III-4 (1I) (MZSP67426) [MZSP]; iv.2012, AP-X-III-1 (1W) [DZUP]; AP-X-III-2 (1W) [USNM]; AP-X-III-3 (1I) (MZSP67427) [MZSP]; julho/2012, AP-X-III-2 (1W) [MCZC]; AP-X-III-4 (1I) (MZSP67428) [MZSP]; x.2012, AP-X-III-2 (1I) [MCZC]; janeiro/2013, AP-X-III-1 (1I) [CASC]; AP-X-III-2 (2I) [DZUP]; AP-X-III-3 (2I) [IHVL, JTCL]; abril/2013, AP-X-III-3 (1I) [USNM]; julho/2013, APX-III-4 (1I) [CASC].