Eurhopalothrix omnivaga

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Eurhopalothrix omnivaga
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Eurhopalothrix
Species: E. omnivaga
Binomial name
Eurhopalothrix omnivaga
Taylor, 1990

Eurhopalothrix omnivaga casent0900936 p 1 high.jpg

Eurhopalothrix omnivaga casent0900936 d 1 high.jpg

Specimen Labels

The type specimens were collected from Berlese funnel extractions of rainforest leaf-litter or mould.

Identification

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo, Indonesia, Malaysia (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

Nomenclature

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

  • omnivaga. Eurhopalothrix omnivaga Taylor, 1990b: 413, figs. 24-26, 50 (w.q.) WEST MALAYSIA.

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

Description

Worker

All Class A attributes present, with those of Class B, unless otherwise indicated. Dimensions (mm): HL 0.66; HW 0.71; CI 108; ML 0.21; MI 32; SL 0.42; SI 59; PW 0.44; WL 0.81. Posterior borders of mandibles oblique, framing a narrow, roughly triangular transverse gap against the clypeus when closed. Eyes moderately large, with 6-8 facets. Occipital border broadly, distinctly, but relatively very shallowly emarginate; posterior occipital angles almost obliterated, broadly rounded and very obtuse (about 120°). Petiolar node in dorsal view essentially square, its length and breadth subequal (any bias longitudinal). One pair of specialised enlarged hairs only on frons, each hair clavate, barely expanded, very slender, almost parallel-sided and apically pointed. Such hairs are apparently normally lacking on promesonotum, petiolar node, postpetiole, and dorsum of first gastral tergite; a few large hairs, as usual, at the gastral apex. Ground pilosity almost lacking, except a few small hairs on the postpetiolar dorsum, scapes, tibiae and tarsi, and exceedingly minute hairs in the punctures of the first gastral tergum.

Mainland Malaysian specimens and those from the Kuching area collectively have HW 0.66-0.75; the 3 from Gunong Mulu 0.65-0.70; those from Sabah 0.63-0.68, and specimens from Sulawesi 0•63-0•66. Reduction in average size of E. omnivaga workers from west to east thus seems evident. The series from Liwa, Sumatra, has the largest specimens of all with HW 0.73-0.78.

Queen

General features as in the worker, with the usual differences of full alate sexuality. Specialised posterior cephalic hairs as in worker. Additional such hairs (maximum known complement; apart from those at the gastral apex) as follows: a single hair above each eye [represented in 4 of 7 specimens (these from Sungei Simei Falls, Quoin Hill and Sepilok), and thus probably easily lost]; those of pronotum, scutum and scutellum as described for Eurhopalothrix jennya (and apparently homologous); a single posterolateral pair on postpetiole, apparently homologous with those of other species (although they are lacking on E. omnivaga workers); gastral hairs more abundant than in the worker, less-clearly deployed in longitudinal rows (again similar to the condition in E. jennya). The mesosomal hairs seem to be easily shed, and most specimens have an incomplete complement.

Type Material

W. Malaysia: Selangor: Ulu Combak Field Station, near Kula Lumpur (03°08'N., 101°42'E.). All specimens from Berlese funnel extractions of rainforest leaf litter or mould. Holotype and most paratypes in Australian National Insect Collection (type No. 7780); holotype gold-palladium coated for SEM study. Worker paratypes in The Natural History Museum, Bernice P. Bishop Museum, Los Angeles County Museum of Natural History, Musee d'Histoire Naturelle Genève, MKUB, MKUC.

References

  • Taylor, R. W. 1990c. New Asian ants of the tribe Basicerotini, with an on-line computer interactive key to the twenty-six known Indo-Australian species (Hymenoptera: Formicidae: Myrmicinae). Invertebr. Taxon. 4: 397-425 (page 413, figs. 24-26, 50 worker, queen described)