Eurhopalothrix seguensis

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

Eurhopalothrix-seguensis-lateral-am-lg.jpg

Eurhopalothrix-seguensis-am-lg.jpg

Holotype Specimen Label

The single type specimen, a worker, was collected from from rainforest leaf mould berlesate.

Identification

Mezger & Pfeiffer (2010) - Separated from all other species by combination of four distinct setae on posterior section of head. Medium pair of these setae close together at midline of head, other pair wider sepa-rated and closer to occiput. Each of these setae 0.04 mm long. Postpetiole with one seta at each side. Eye with 20 ommatidia. Ground pilosity less dense with mean distance of squamiform hairs 18 μm and diameter of foveolae around 28 μm, i.e., distances between squamiform hairs large and resembling Eurhopalothrix elke, but diameter of foveolae more similar to Eurhopalothrix platisquama. Scape with two rows of setae, one outer row with seven setae and one inner row with nine setae (Fig. 16). Mandible 1.1 times as broad as long. Due to extensive gold-coverage for former SEM studies no information on number of teeth available.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo (type locality), Indonesia, Malaysia.

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.

  • seguensis. Eurhopalothrix seguensis Taylor, 1990b: 421, figs. 34, 41-43, 55 (w.) BORNEO.

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 0.71; HW 0.79; CI 112; ML 0.19; MI 27; SL 0.41; SI 52; PW 0.48; WL 0.83. Eyes large, as in Eurhopalothrix platisquama. Occipital border almost straight, transverse (its outline at most minutely curved or sinuous). Posterior occipital angles obtusely rounded, forming angles of about 130°. Mesosomal profile not a continuous curve, its outline interrupted at the promesonotal/propodeal junction by a minute indentation; the mesometanotal suture not incised dorsally to break the surrounding sculpture. Petiolar node in dorsal view essentially square, its length and breadth sub equal (bias transverse).

Frons and most dorsal body surfaces with ground pilosity of dense, flattened, appressed, squamous, shining silvery hairs, which are less strongly developed than in E. platisquama and Eurhopalothrix dubia, so as barely to overlap the punctures in which they lie, which remain more clearly visible than in the other species mentioned. Four relatively short specialised hairs on posterior occipital border, the median pair adjacent, the laterals each about midway between them and the posterior occipital angles; the hairs clavate, barely expanded, though somewhat thick and columnar. Erect hairs lacking elsewhere on promesonotum, petiolar node and dorsum of first gastral tergite; one pair (posterolateral) on postpetiole.

Type Material

Malaysia: Sarawak: First Division: Kampong Segu, 20 miles S.W. of Kuching (01°33'N.,110°20'E.). Known only from the unique worker holotype, from a rainforest leaf mould berlesate (RWT acc 68 .289, 4.vi.1968). In Australian National Insect Collection (type No. 7783); gold-palladium coated for SEM study.

Etymology

Named for the type locality.

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