Eurhopalothrix greensladei

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Eurhopalothrix greensladei
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Eurhopalothrix
Species: E. greensladei
Binomial name
Eurhopalothrix greensladei
Taylor, 1968

The type material was collected from rainforest leaf litter.

Identification

P. greensladei is probably cognate with Eurhopalothrix procera. It is remarkably intermediate in structure between procera and Eurhopalothrix isabellae. Most of the characters listed above, which distinguish greensladei from procera, are present also in isabellae, frequently in a more exaggerated state. Furthermore, several extreme characters of isabellae (notably the aberrant mandibular form, the heavy mesosomal sculpturation, and the very reduced vestiture) are foreshadowed in greensladei. (Taylor 1968)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Solomon Islands (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.

  • greensladei. Eurhopalothrix greensladei Taylor, 1968b: 342, figs. 6, 7 (w.) SOLOMON IS.

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

Description

Worker

Dimensions (holotype cited first): TL c. 4.2, 4.0-4.6, HL, 0.94, 0.92-0.98; HW, 1.05, 1.03-1.08; CI, 112, 110-114; ML, 0.26, 0.25-0.27; MI, 28, 27-28; SL, 0.56, 0.54-0.57; SI, 53, 52-53; greatest diameter of eye, 0.08, 0.08-0.09; PW, 0.60, 0.58-0.61; WL, 1.13, 1.10-1.14; petiolar node width, 0.25, 0.24-0.26; postpetiole width 0.61, 0.57-0.62; gastric width, 0.82, 0.78-0.83. Similar to Eurhopalothrix procera but differing from its Guadalcanal race, as described above, in the following characters:

(1) Size and proportions: smaller size, with relatively broad head (higher CI), short mandibles (lower MI), and short scapes (lower SI).

(2) Outer mandibular borders feebly but distinctly concave.

(3) Pronotal gibbosities very feeble; the dorsum of the sclerite barely depressed in the middle.

(4) Promesonotal sulcus lacking on dorsum of mesosoma and vestigial on its sides. Promesonotal dorsum, in side view, less strongly inflated.

(5) Dorsum of petiolar node slightly longer than broad.

(6) Ventral edge of subpetiolar process entire, lacking serrations.

(7) Postpetiolar tumosities weakly developed, relatively obtuse; the depression between them maximally about o• 1 times as deep as the distance between their apices.

(8) Sculpturation of mandibles, antennae, and legs as in Guadalcanal procera. Clypeus moderately shining, with almost effaced traces of dense, coarse puncturation. Frons moderately shining, with scattered, weakly incised, large punctures (average diameter and distance of separation about 0.02 mm). Promesonotal dorsum very coarsely longitudinally rugo-reticulate. Dorsum and sides of propodeum subopaque, coarsely and irregularly punctate; declivity finely granulose. Sides of mesosoma coarsely punctate, except for small areas on inferior edges of pronotum, and lower parts of the mes- and metepisterna, which are smooth, with a few scattered large punctures. Petiole and postpetiole moderately coarsely granulose-punctate, most strongly on petiolar dorsum and apices of postpetiolar tumosities. Gastric puncturation much less sharply and clearly incised than in procera.

(9) Vestiture much weaker, except on legs and antennae. Hairs of ground pilosity smaller; very scattered on clypeus, lacking on frons (except for a few on outer corners of occipital lobes); moderately abundant, though not prominent, on promesonotum and petiolar dorsum; generally restricted on postpetiolar dorsum to apices of lateral tumosities. One bilateral pair of erect, bristle-like, feebly clavate hairs each on verticocciput and pronotal humeri. Erect hairs completely lacking on first gastric tergite. Second and third gastric tergites each with a single transverse row of erect, feebly clavate bristles; similar but less clavate bristles moderately abundant at apex of gaster and on its venter, the most anterior lying at about mid-length of first sternite.

(10) Colour dark reddish brown; mandibles, clypeus, antennae, legs and tip of gaster lighter.

Type Material

Holotype worker. British Solomon Islands: Guadalcanl: Mt. Austen (Berlese funnel sample, leaf litter, secondary rain forest c. 1000 ft), 21.iv.l965, P. J. M. Greenslade (Acc. No. 16991). Deposited in Museum of Comparative Zoology (Type No. 31180). Paratype workers. Guadalcanal: Mt. Austen, four specimens collected with the holotype and nine collected separately in leaf litter, Berlese funnel samples (each record a single specimen unless otherwise noted), ll.ii.1963, 25.iv.1963, 29.xi.1963, February 1966 (2 specimens), March 1966 (4 specimens). Kukum, in decayed log, 22.vi.l963. All material collected by Dr. or Mrs. P. J. M. Greenslade (Acc. Nos. 4290, 6314, 11048, 21210, 21316, 6779). Deposited in Australian National Insect Collection, The Natural History Museum, BSI, MCZ, National Museum of Natural History. Mt. Austen (9°28'S., 159°59'E.) is 4 miles inland from Kukum, which is a Solomon Is. Department of Agriculture farm on the coast, about 4 miles east of Honiara.

References

  • Taylor, R. W. 1968c. Notes on the Indo-Australian basicerotine ants (Hymenoptera: Formicidae). Aust. J. Zool. 16: 333-348 (page 342, figs. 6, 7 worker described)