Eurhopalothrix alopeciosa

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Eurhopalothrix alopeciosa
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Eurhopalothrix
Species: E. alopeciosa
Binomial name
Eurhopalothrix alopeciosa
Brown & Kempf, 1960

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Specimen Labels

Known only from the types.


Longino (2013): This species is most similar to Eurhopalothrix pilulifera and Eurhopalothrix clypeata, sharing the small size; a similar arrangement and number of erect setae, these almost circular, nearly as broad as wide; and abundant ground pilosity that is strongly flattened and conspicuous. Eurhopalothrix clypeata has a transverse carina on the clypeus. Eurhopalothrix pilulifera has the propodeal spine in the form of a rectangular lamella extending down the posterior face of the propodeum (propodeal spine acute in E. alopeciosa, with narrow infradental lamella). Eurhopalothrix xibalba is larger and has thinner ground pilosity. Measurements for this species, from Brown and Kempf (1960), are HW 0.50–0.53, HL 0.52, SL 0.32, CI 96.

Keys including this Species


Distribution based on Regional Taxon Lists

Neotropical Region: Ecuador, Trinidad and Tobago (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


Little is known about the biology of most species in this genus. Nests are rarely found, and queens and males have not been collected for many species. Longino (2013) summarized their biology "Eurhopalothrix specimens are encountered almost exclusively in samples from mass extraction techniques that recover small arthropods in sifted litter, rotten wood, and soil. Densities, at least in the northern Neotropics, are usually low, with workers occurring in < 10% of quantitative samples of 1 m2 litter plots, but occasionally may reach densities as high as 40% of samples. Live colonies of Old World Eurhopalothrix were observed by Wilson (1956) and Wilson and Brown (1984), and a Costa Rican colony of Basiceros manni was observed by Wilson and Hölldobler (1986). All basicerotines, including Eurhopalothrix, are thought to be predators in tropical leaf litter, relying on stealth or sit-and-wait techniques. Sampled specimens are often coated with a thin layer of clay, especially on the face, which is thought to function as camouflage, enhancing crypsis (Hölldobler & Wilson, 1986). Highly specialized spatulate setae may be instrumental in acquisition and adherence of the clay layer (Hölldobler & Wilson, 1986)."


Known only from the worker caste.


The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • alopeciosa. Eurhopalothrix alopeciosa Brown & Kempf, 1960: 206 (w.) TRINIDAD.

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



Holotype. TL 2.0, HL 0.52, H W 0.50 (CI 96), scape L 0.32, greatest eye diameter about 0.02, WL 0.50 mm.

Combines characters of clypeata and pilulifera. Head shape as in clypeata, but the c1ypeus of the usual form, not transversely carinate (very feebly convex, with shallowly depressed anterior margin ) . Pilosity of head arranged as in clypeata, except that a few small appressed hairs of the ground pilosity are scattered over the "bald space" occupied otherwise by the large specialized hairs. Clypeus set evenly with small squamiform hairs throughout, as are also the mandibles, dorsal scape surfaces, anterior half of head above and sides of occiput, and promesonotum, petiolar node, postpetiole and gastric dorsum. The ground pilosity is similar to that of pilulifera, but the individual ground hairs are more orbicular, larger and more abundant. The large specialized hairs are prevailingly subspherical or "pompon-like", relatively broader than those of clypeata and perhaps even of pilulifera, especially on gastric dorsum, where they form an irregular double row (4-5 pairs ) down the middle of the first tergite, the double row flanked on each side by 2 or 3 additional hairs representing vestigial longitudinal rows. The usual clavate or truncate hairs are present on the gastric apex, and the hair on each tibial apex is pompon-like.

Body form otherwise and color much as in Eurhopalothrix clypeata.

Type Material

Holotype a worker [NAW] from Trinidad, British West Indies (N. A. Weber leg., No. 162.2). A paratype worker [MCZ] from Maracas Valley, Trinidad, March 23, 1935 (Weber leg., No. 76), is similar to the holotype, but is somewhat damaged; it is a little larger than the holotype and has a relatively broader head: HW about 0.53 (CI about 101); WL 0.52 mm.


  • Brown, W. L., Jr.; Kempf, W. W. 1960. A world revision of the ant tribe Basicerotini. Stud. Entomol. (n.s.) 3: 161-250 (page 206, worker described)
  • Longino J. T. 2013. A review of the Central American and Caribbean species of the ant genus Eurhopalothrix Brown and Kempf, 1961 (Hymenoptera, Formicidae), with a key to New World species. Zootaxa. 3693:101-151. doi:10.11646/zootaxa.3693.2.1