Eurhopalothrix szentivanyi

Every Ant Tells a Story - And Scientists Explain Their Stories Here
Jump to navigation Jump to search
Eurhopalothrix szentivanyi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Eurhopalothrix
Species: E. szentivanyi
Binomial name
Eurhopalothrix szentivanyi
Taylor, 1968

Eurhopalothrix szentivanyi casent0280768 p 1 high.jpg

Eurhopalothrix szentivanyi casent0280768 d 1 high.jpg

Specimen Labels

The type workers were collected from a rotting log in lower montane oak-Araucaria hunsteinii rain forest.


Keys including this Species


Distribution based on Regional Taxon Lists

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

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


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)."



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

  • szentivanyi. Eurhopalothrix szentivanyi Taylor, 1968b: 346, figs. 12-15 (w.q.) NEW GUINEA.

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



Dimensions (holotype cited first): TL, c. 5.6, 5.4-6.0; HL, 1.28, 1.27-1.33; HW, 1.41, 1.34-1.45; CI, 110, 106-110; ML, 0.46, 0.45-0.48; MI, 36, 35-36; SL, 0.77, 0.74-0.79; SI, 55, 54-55; greatest diameter of eye, 0.15, 0.13-0.17; PW, 0.85, 0.82-0.88; WL, 1.56, 1.48-1.62; petiolar node width, 0.34, 0.32-0.36; postpetiole width, 0.73,0.71-0.76. Frons moderately inflated, frontal tumosities feebly developed. Basal mandibular and anterior clypeal borders enclosing a large semicircular gap at full mandibular closure. Labrum tongue-shaped, slightly longer than basal width, apex broadly rounded. Face of scape strongly convex, longitudinally grooved along outer edge. Promesonotum strongly vaulted, much higher than propodeum. Humeri rounded in dorsal view; pronotal gibbosities feebly inflated. Promesonotal sulcus a faint, shallow impression on mesosomal dorsum, not incised above spiracles. Metanotal groove distinct, transversely ribbed. Propodeal spines small, diverging from midline at angles of about 45°, bases connected by a fine transverse carina; infradentallamellae reduced to fine carinae. Dorsum of node about as wide as long. Subpetiolar process with vestiges of serrations probably homologous with those of Eurhopalothrix procera. Postpetiole about two-thirds as long as broad; dorsolateral tumosities moderately developed. Gaster about 1.4 times wider than postpetiole.

Mandibles shining, moderately coarsely and closely punctate. Scapes finely granulose. Clypeus moderately shining, with effaced coarse puncturation. Frons very shiny, with irregularly scattered foveolate punctures, separated by distances of 2-3 times their average diameter (c. 0.025 mm). Mesosoma mostly smooth on sides and along a narrow median longitudinal strip; these surfaces shining, with a hazy bluish "bloom". The following areas coarsely punctate-rugose: a narrow band across pro notal collar, extending to inferior angles laterally; an approximately triangular dorsolateral patch on each pro notal humerus; sides and posterodorsal parts of propodeum. Front and sides of pronotum and anterior propodeal dorsum with a few scattered foveolate punctures. Mesonotum with a narrow longitudinal band of foveolate punctures on each side of median strip. Propodeal declivity finely granulose.

Dorsolateral aspects of node and postpetiole coarsely punctate-rugose, both segments with a hazily shining median longitudinal strip. First gastric tergite smooth, strongly reflective, with a few weakly incised foveolate punctures, and without a bluish bloom, which is present on sternite. Truncate anterior face of first gastric segment granulose (like propodeal declivity). Apical gastric sclerites weakly shagreened; traces of such sculpturation on extreme sides and posterior edge of first tergite, and on posterior third of its sternite, which also bears a few obscure coarse punctures. Legs generally finely granulose.

Ground pilosity of 0.03-0.08 mm long, moderately clavate white hairs, abundant on clypeus, frontal lobes, scapes and postgenal areas; smaller and less abundant on frons, except around eyes and edges of occipital lobes. Mandibular pilosity very reduced, except for bristle-like hairs among the teeth. Funiculi finely pubescent. Hairs like those of clypeus abundant on sculptured areas of mesosoma and nodes, which are otherwise virtually naked. Legs, except outer coxal surfaces, with dense, short, thick, clavate hairs. Gastric pilosity reduced; a few long clavate hairs at apex, shorter ones on sculptured area of first sternite. Erect specialized pilosity reduced to a single bilateral pair of verticoccipital hairs, c. 0•07 mm long.

Colour dark reddish brown, almost black, gaster slightly lighter. Clypeus, frontal lobes, and area of propodeal-petiolar junction infuscated medium reddish brown. Mandibles, antennae, and legs medium sienna-brown.

Type Material

Holotype worker. N.E. New Guinea: Bulolo River Valley, 6 km NE. of Wau (ex rotting log, lower montane oak-Araucaria hunsteinii rain forest, 1100 m), July 1962, R. W. Taylor (Ace. No. 1917). Deposited in Museum of Comparative Zoology (Type No. 31181). Paratypes. Four workers with same data as holotype (nidoparatypes), deposited in Australian National Insect Collection, Bernice P. Bishop Museum, MCZ, National Museum of Natural History. A dealate queen from the same locality (ex Zoraptera-stage rotting log), R. W. Taylor (Ace. No. 2013), deposited in ANIC.


This elegant species is named for Dr. J. J. H. Szent-Ivany in appreciation of his splendid assistance and hospitality during the author's New Guinea field studies.


Dimensions: TL, c. 6.7; HL, 1.40; HW, 1.55; CI, 111; ML, 0.49; MI, 35; SL, 0.82; greatest diameter of eye, 0.27; WL, 1.85. Similar to worker, but with ocelli and complete mesosomal structure. Pronotum with coarsely granulose humeral patches, mesoscutum somewhat indefinitely longitudinally sculptured, with a depressed smooth posteromedian area. Scutellum coarsely punctate-rugose, with a slight longitudinal trend. Ground pilosity as in worker, scutum and scutellum with a few indistinct small hairs. Bilaterally paired erect specialised hairs on verticocciput and mesosomal dorsum.


  • Taylor, R. W. 1968c. Notes on the Indo-Australian basicerotine ants (Hymenoptera: Formicidae). Aust. J. Zool. 16: 333-348 (page 346, figs. 12-15 worker, queen described)