Eurhopalothrix speciosa

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

Eurhopalothrix speciosa casent0280767 p 1 high.jpg

Eurhopalothrix speciosa casent0280767 d 1 high.jpg

Specimen Labels

The types were collected from sifted leaf mold; nothing is known about the biology of Eurhopalothrix speciosa.

Identification

Longino (2013): This species shares the elevated posterior mesonotal keel with Eurhopalothrix hunhau and Eurhopalothrix sepultura. Eurhopalothrix hunhau has a full complement of 18 specialized setae on the face; both E. sepultura and E. speciosa have a reduced number. The head shape of E. speciosa is very similar to E. sepultura. Eurhopalothrix speciosa has a distinctive arrangement of 6 specialized setae on the face: 4 in a tight square on the posteromedian vertex, and 2 on the posterolateral angles of the vertex margin. In contrast, Eurhopalothrix sepultura has the same medial square of 4 setae, but 4–6 additional setae are arranged anteriorly, between the medial square and the compound eyes, and there are no setae on the posterolateral angles of the vertex margin. Also, the compound eye of E. speciosa is relatively large, with 7–8 ommatidia across greatest diameter, versus 5 in E. sepultura.

Keys including this Species

Distribution

Brazil (Santa Catarina, Sao Paulo)

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

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)."

Castes

Known only from the worker caste.

Nomenclature

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

  • speciosa. Eurhopalothrix speciosa Brown & Kempf, 1960: 203, figs. 31-33 (w.) BRAZIL.

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

Description

Worker

Holotype: TL 2.8, HL 0.76, H W 0.78 (CI 103), scape L 0.49, maximum diameter of compound eye 0.09, WL 0.72 mm. Form of head and body as shown in the figures.

This is a medium-sized member of the bolaui group notable for the reduction of its pilosity. The appressed and subappressed ground pilosity consists of small to minute, mostly simple hairs, rather dense on mandibles and clypeus, sparse on dorsum of nodes and gaster, and very sparse and inconspicuous on vertex, occiput and alitruncal dorsum. Simple appressed small hairs of the legs give way on the tibiae, especially the flexor surfaces, to appressed and decumbent spatulate hairs. Extensor apical point of each tibia with the short, thick clavate hair usual for the genus. The larger specialized hairs are thick-squamiform, reduced in number on the head, and are set in marginate foveae that tend to be more distinct than in related species. The close rectangular group on the median field of the occiput is especially characteristic. Humeral pair absent on holotype and both paratypes, indicating that they are probably truly lacking and not just rubbed off. The two pairs of mesonotal hairs are exceptionally large and thick, and the posterior pair is set in contiguous foveae separated by a short longitudinal carina. Other hairs of the large type arranged as usual in this group of species; median postpetiolar pair small. Promesonotal suture virtually obsolete; metanotal groove present but indistinct. Body densely punctulate-granulose, opaque; dorsum of head finely rugulose in addition. Clypeus and gaster finely and densely punctulate, subopaque (narrow interspaces mostly individually shining). Mandibles almost smooth, moderately shining, with about 8 or 9 teeth (not dissected). Color medium ferruginous; legs and pleura more yellowish.

The Plaumann collected paratype is larger than the holotype: TL 3.3, HL 0.87, HW 0.89 (CI 102), scape L 0.54, maximum diameter of eye 0.12, WL 0.85 mm. Front of head more irregularly rugulose, the sculpture less longitudinally oriented; dorsum of alitrunk more rugulose. Large hairs on occiput and mesonotum less strongly inflated. Otherwise similar to holotype.

Type Material

Longino (2013) - Holotype worker: Brazil, Santa Catarina: Nova Teutonia, May 1957, sifted from leaf mold (F. Plaumann) Museu de Zoologia da Universidade de Sao Paulo, WWK No. 2648] (not examined). Paratype workers: same data as holotype Museum of Comparative Zoology; Serra Geral, Dec 1958, sifted from leaf mold (F. Plaumann) MZSP, WWK No. 3004.

References

  • Brown, W. L., Jr.; Kempf, W. W. 1960. A world revision of the ant tribe Basicerotini. Stud. Entomol. (n.s.) 3: 161-250 (page 203, figs. 31-33 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