Pristomyrmex foveolatus

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Pristomyrmex foveolatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Pristomyrmex
Species: P. foveolatus
Binomial name
Pristomyrmex foveolatus
Taylor, 1965

MCZ-ENT00031152 Pristomyrmex foveolatus hal.jpg

MCZ-ENT00031152 Pristomyrmex foveolatus had.jpg

Type Specimen Label

This species occurs only in rainforest in North Queensland, Australia, and has been collected in litter berlesates; its nests are constructed in rotting logs (Taylor, 1965).

Identification

Wang (2003) - Worker. Pronotum with a pair of triangular short spines (ca. 0.06-0.13); propodeal spines long (ca. 0.20-0.30); dorsum of head, except for the antennal scrobes, with foveolate-reticulate sculpture ; postpetiole unsculptured; PPI 133-150; SL 0.70-0.82 and SI 81-93.

Pristomyrmex foveolatus is extremely similar to Pristomyrmex thoracicus, also from Australia, in many characters in the workers and queens, such as (1) the dentition of the masticatory margin of mandible, (2) palp formula, (3) structure and shape of the clypeus, (4) length and shape of the pronotal and propodeal spines, and (5) sculpture of the dorsal surfaces of the head and the alitrunk. The differences between the workers of these two species are slight, as follows: P. foveolatus - Antennal scapes shorter (SL 0.70- 0.82, SI 81-93). Postpetiole in dorsal view much broader than long, PPI 133- 150, with the two sides subparallel, showing a transverse rectangle. P. thoracicus - Antennal scapes longer (SL 0.86- 0.98, SI97- 103). Postpetiole in dorsal view slightly broader than long, PPI 109-121, with the two sides not subparallel, showing a trapezoid.

A member of the quadridens species group.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The biology of most Pristomyrmex species is poorly known. From Wang (2003): Most species of Pristomyrmex dwell in the rainforest, foraging as predators or scavengers. An Asian species, Pristomyrmex punctatus, however, occurs in open and disturbed habitats (e.g., bare hills, agricultural areas, and beaches). These ants prefer to nest in soil, litter, or rotten wood; in rotten parts of living trees; in dead standing trees; or around plant roots.

Pristomyrmex is of great interest because it exhibits several unusual biological and evolutionary phenomena. The absence of morphologically normal queens and reproduction primarily by unmated workers in P. punctatus {=P. pungens) is a highly unusual life history in the Formicidae. Ergatoid queens, a special wingless female caste morphologically intermediate between the queen and the worker, are present in at least four species: Pristomyrmex punctatus, Pristomyrmex africanus, Pristomyrmex wheeleri, and Pristomyrmex mandibularis; two of them (P. africanus and P. wheeleri) possess both queen and ergatoid queen castes.

Simulating death, slowness of movement, and nocturnal foraging has been recorded in Pristomyrmex (Donisthorpe, 1946; Taylor, 1965; Weber, 1941). Colony size varies greatly among species, ranging from about a dozen to several thousand workers (Donisthorpe, 1946; Itow et al, 1984; Mann, 1919; Taylor, 1965, 1968).

Castes

Nomenclature

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

  • foveolatus. Pristomyrmex foveolatus Taylor, 1965b: 38, figs. 1, 2 (w.) AUSTRALIA. Wang, M. 2003: 447 (m.).

Type Material

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

Description

Worker

Wang (2003) - TL 2.74-3.26, HL 0.78-0.92, HW 0.80-0.96, C1 100-108, SL 0.70-0.82, S1 81-93, EL 0.11-0.14, PW 0.50-0.62, AL 0.68-0.86, PPYV 0.23-0.27, PPL 0.16-0.20, PP1 133-150 (n = 74).

Mandibles usually with a few longitudinal rugae. Masticatory margin of mandible with three teeth: an apical + a preapical + a long diastema + a truncated basal tooth. Basal margin of mandible lacking a distinctly curved lobe or tooth. Clypeus with a strong median carina. Anterior clypeal margin with a median denticle and usually two to three others on each side; two or three lateral denticles are often fused into one prominence. Ventral center of clypeus with a low, broad, toothlike prominence. Palp formula 2,3. Frontal carinae well-developed, beyond the level of the posterior margins of eyes. Scrobal areas shallow, pre sent below the frontal carinae. Frontal lobes almost completely absent so that the antennal articulations are entirely exposed. Antennal scapes, when lying in the antennal scrobes, close to or just reaching the occipital margin of head. Eyes containing five to six ommatidia in the longest row. Pronotum armed with a pair of short spines (ca. 0.06-0.13). Propodeal spines long, ca. 0.20 to 0.30, usually straight but sometimes slightly upcurved along their length. Metapleural lobe small-triangular, usually with an acute apex. Petiole node in profile higher than long, with a long anterior peduncle, its anterodorsal angle forming an apex and its dorsum sloping downward posteriorly. Postpetiole in profile much higher than long, with a rounded dorsum; in dorsal view, postpetiole transverse-rectangled , much broader than long, with the two sides subparallel. Dorsum of head, except for the antennal scrobes where there are only a few transverse rugae, with well-developed foveolate-reticulate sculpture. Dorsum of alitrunk usually with foveolate-reticulate sculpture and a few coarse longitudinal rugae. Sides of pronotum with a few foveolate punctures; sides of the rest of alitrunk with some irregularly superficial rugae. Petiole node and postpetiole smooth and shining. Gaster unsculptured. Dorsal surfaces of head and alitrunk with numerous erect or suberect long hairs. Dorsal surfaces of petiole node and postpetiole with a pair of long hairs. First gastral tergite lacking erect or suberect hairs. A few pairs of forward-projecting hairs present near the anterior clypeal margin. Scapes and tibiae with some erect to suberect short hairs. Color reddish-brown.

Queen

Wang (2003) - TL 3.20, HL 0.8.3, HW 0 .86, CI 104, SL 0.74, SI 86, EL 0.16, PW 0.66, AL 0.87, PPW 0.2.5, PPL 0.16, PP1 139 (n = 1).

General shape with normal caste differences from the conspecific worker; pronotum unarmed; other characters similar to worker; propodeal spine length 0.25.

References

  • Taylor, R. W. 1965b. The Australian ants of the genus Pristomyrmex, with a case of apparent character displacement. Psyche (Camb.) 72: 35-54 (page 38, figs. 1, 2 worker described)
  • Wang, M. 2003. A Monographic Revision of the Ant Genus Pristomyrmex (Hymenoptera:Formicidae). Bull. Mus. Comp. Zool. 157(6): 383-542 (page 446, figs 140-143 queen described)