Eurhopalothrix australis

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to navigation Jump to search
Eurhopalothrix australis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Eurhopalothrix
Species: E. australis
Binomial name
Eurhopalothrix australis
Brown & Kempf, 1960

Eurhopalothrix australis casent0172464 profile 1.jpg

Eurhopalothrix australis casent0172464 dorsal 1.jpg

Specimen labels

The types are part of a nest series collected from rainforest. This species is unusual for the genus in that it is been collected many times.

Identification

Keys including this Species

Distribution

Occurs in habitats that vary from open to heavily forested in areas along and near the coast of eastern Queensland and northern New South Wales.

Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps

AntMapLegend.png

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.

  • australis. Eurhopalothrix australis Brown & Kempf, 1960: 218, figs. 46, 51 (w.q.) AUSTRALIA. Wheeler, G.C. & Wheeler, J. 1973c: 207 (l.).

Type Material

  • Holotype, worker, near Crawford's Lookout by the Beatrice River, Millaa-Millaa-Innisfail Highway descending from the Atherton Tableland, Queensland, Australia, February, 1958, P.F. Darlington, Museum of Comparative Zoology; rain forest.
  • Paratype, 8 workers, 1 queen, near Crawford's Lookout by the Beatrice River, Millaa-Millaa-Innisfail Highway descending from the Atherton Tableland, Queensland, Australia, February, 1958, P.F. Darlington, Museum of Comparative Zoology, WWK, an Australian Collection as yet unselected; rain forest.
  • Paratype, 1 worker, Mt. Coot-tha, near Brisbane, Queensland, Australia, 20 December, 1956, B.B. Lowery, Australian National Insect Collection; in soil.

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 2.2. HL .056. HW 0.60 (Cl 107), scape L 0.33, greatest diameter o f eye ca. 0.04, WL 0.59 mm.

Form of head shown in Figure. General habitus as in Eurhopalothrix brevicornis and relatives; size larger than brevicornis, smaller than Eurhopalothrix caledonica. Clypeus anteriorly plane and sloping forward, with a shallowly impressed median part; posterior median lobe gently convex, without a transverse ridge. Mandibles each with 11 acute teeth (including apical tooth); basal tooth (tooth No. 1) broader at base than the rest; Nos. 1, 3, 5, 7 shorter than 2, 4, 6, 8, 11; Nos. 9 and 10 denticuliform, indistinct.

Promesonotum long, with flat dorsal surface (disc feebly impressed in some specimens); metanotal groove distinct, impressed; propodeal dorsum predominantly concave in outline, sloping caudad and continued as the broad lamelliform propodeal teeth. Petiole with peduncle and node subequal in length; node subangular in front above, its dorsal face convex, sloping behind, higher than long and, as seen from above, broader than long, with concave anterior border and weakly convex sides. Postpetiole about twice as wide as petiole and nearly 3/4 as wide as widest part of gaster (as wide as anterior border of gaster).

Pilosity of head of the "complete" type for the brevicornis group, but with the "bald spot" as in Eurhopalothrix clypeata, Eurhopalothrix alopeciosa and some Eurhopalothrix gravis, in which the small ground hairs are sparser and the whitish matter (a secretion?) often found on other surfaces of the head is absent. Subappressed spatulate hairs of the ground pilosity evenly distributed over legs, scapes, postpetiole and gaster, sparser on petiole and promesonotum, very fine and small on mandibles. No larger specialized hairs on alitrunk, one pair on petiolar node, and one pair on postpetiole (one hair on each posterolateral corner ); 14-18 hairs on first gastric tergite, a double row down the middle of the disc, another row flanking these on each side, often incomplete anteriad. The first and the two succeeding tergites each bear a total of 6 hairs in a transverse row near the free margin caudad. The specialized hairs are short but robust and obliquely erect, thicker and more numerous on the gastric dorsum than in brevicornis, and shorter, broader and less numerous than in caledonica.

Body densely and finely granulose-punctate, as in other members of the brevicornis group. Color medium ferruginous, legs and antennae more yellowish.

Paratype workers : TL 2.0-2.4, HL 0.54-0.57, HW 0.58-0.62 (CI 106-109), WL 0.57-0.60 mm. In some specimens the lateral occipital lobes are slightly more angulate at their point of greatest extension, and the sloping lateral borders of the lobes are correspondingly feebly concave. Several specimens, evidently rubbed, lack parts of the pilosity, especially the larger hairs. Otherwise, the paratypes are very similar to the holotype.

Queen

Alate, Paratype: TL 2.8, H L 0.62, H W 0.66 (CI 106), WL 0.75, forewing WL ca. 2.6 mm. With the usual caste differences. Mesonotum with 10 short spatulate erect hairs, mostly near the margins. Petiolar node much compressed anteroposteriorly, narrowly angulate above in front. Venation of forewing basically as in Eurhopalothrix procera,. but with pterostigma more distinct and with veins M + CuA and the apical sections of Rs, M and Cu deleted. Taken with the holotype; deposited in MCZ.

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 218, figs. 46, 51 worker, queen described)
  • Wheeler, G. C.; Wheeler, J. 1973c. The ant larvae of the tribes Basicerotini and Dacetini: second supplement (Hymenoptera: Formicidae: Myrmicinae). Pan-Pac. Entomol. 49: 207-214 (page 207, larva described)