Eurhopalothrix brevicornis

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Eurhopalothrix brevicornis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Eurhopalothrix
Species: E. brevicornis
Binomial name
Eurhopalothrix brevicornis
(Emery, 1897)

Eurhopalothrix brevicornis casent0280769 p 1 high.jpg

Eurhopalothrix brevicornis casent0280769 d 1 high.jpg

Specimen Labels

Synonyms

E. O. Wilson collected a small series of workers and a stray at the Lower Busu River, near Lae, New Guinea, hy Berlese funnel from rain forest leaf litter. The MCZ has two workers taken by K. P. Schmidt from a bird's-nest fern at Rabaul, New Britain. (Brown and Kempf 1960)

Identification

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea (type locality), Solomon Islands.

Check distribution from AntMaps.

Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Eurhopalothrix brevicornis for further details

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

Worker

Nomenclature

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

  • brevicornis. Rhopalothrix brevicornis Emery, 1897c: 572, fig. 19 (w.) NEW GUINEA. Szabó, 1910a: 367 (q.). Combination in Eurhopalothrix: Brown & Kempf, 1960: 215. Senior synonym of mixta: Brown & Kempf, 1960: 215.
  • mixta. Rhopalothrix mixta Szabó, 1910a: 366, fig. 4 (w.) NEW GUINEA. Junior synonym of brevicornis: Brown & Kempf, 1960: 215.

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

Description

Worker

Brown and Kempf (1960) - TL 1.7-1.8, HL 0.42-0.46, HW 0.46-0.50 (CI 109-110), scape L 0.26-0.27, greatest diameter of eye ca. 0.02, WL 0.46-0.47 mm; based on 7 workers from New Guinea and New Britain.

Differs from other members of its group in its smaller size and in shape of alitrunk with its abruptly sloping concave dorsal face of propodeum and small subrectangular propodeal teeth. Also the following distinctive characters:

1. Clypeus traversed by a distinct, arcuate carina, separating a large, concave anterior part (covered with small squamiform hairs and opaque) and a small, feebly convex, triangular posterior part (which is nearly smooth, naked, weakly shining). In this feature, surprisingly, brevicornis resembles Eurhopalothrix clypeata of the New World (q. v.).

2. The arcuate row of 8 large specialized hairs stretching across the vertex between the eyes stands upon a feeble carina that follows the same course. Sometimes a faint trace of such a carina may be seen in other species of the genus, and it appears to be a homologue of the similarly placed carina in Octostruma rugifera, Octostruma rugiferoides, and some of the Rhopalothrix species.

3. Erect specialized hairs short and thick, clavate; 16 on cephalic dorsum; 1 pair straddling mesonotum, in most specimens missing and possibly rubbed off; first gastric tergite with 3 pairs, forming a double longitudinal row, and outside of third (posterior) pair are two more hairs, so that a transverse row of 4 is formed near the posterior edge of the segment. Both petiole and postpetiole lack larger specialized hairs entirely.

4. Petiolar node small and rather rounded above as seen from the side; as seen from above, node transverse, with rounded sides and feebly concave anterior border. Postpetiolar node about twice as wide as petiolar node, and very nearly three times as wide as long, 3/4 as wide as gaster.

5. Ground pilosity of appressed and subappressed hairs well developed on head (except for indistinct "bald area" on verticocciput), mandibles, scapes, promesonotum, legs, both nodes and gastric dorsum. Color medium ferruginous.

Queen

Brown and Kempf (1960) - Female, dealate: TL 2.3, HL 0.52, HW 0.56 (CI 108), scape L 0.31, greatest diameter of eye ca. 0.12, WL 0.62 mm. With the usual differences of caste. Dorsolateral margins of rnesonoturn with 6 short, inconspicuous, subreclinate clavate hairs. Color as in worker.

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 215, Combination in Eurhopalothrix, and senior synonym of mixta)
  • Szabó, J. 1910a. Formicides nouveaux ou peu connus des collections du Musée National Hongrois. [part]. Ann. Hist.-Nat. Mus. Natl. Hung. 8: 364-368 (page 367, queen described)