Pristomyrmex wheeleri

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

MCZ-ENT00031154 Pristomyrmex wheeleri hal.jpg

MCZ-ENT00031154 Pristomyrmex wheeleri had.jpg

Type Specimen Label

This species occurs in rainforest, nesting in the soil, usually under or between rocks, often in a tangle of small plant roots; it probably restricts its foraging activity to the soil and leaf litter (Taylor, 1965, 1968).

Identification

A member of the quadridens species group.

Wang (2003) - Worker. Masticatory margin of mandible with three teeth; anterior clypeal margin at most with three teeth; propodeal spine length ca. 0.18 to 0.28, about equal to or slightly longer than pronotal spines; dorsum of alitrunk smooth, but with a transverse ridge present at the approximate position of metanotal groove; petiole node and postpetiole dorsally with some hairs; first gastral tergite lacking hairs.

Pristomyrmex wheeleri occurs occurs in East Australia. Its two close relatives are Pristomyrmex erythropygus and Pristomyrmex quadridentatus, also from East Australia. Characters separating P. wheeleri from P. erythropygus and from P. quadridentatus are provided under P. erythropygus and under P. quadridentatus, respectively.

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

Males have yet to be collected.

Nomenclature

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

  • wheeleri. Pristomyrmex wheeleri Taylor, 1965b: 48, figs. 11-13; pl. 3 (w.q.) AUSTRALIA. Wang, M. 2003: 480 (q. and ergatoid q.)

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 3.26-4.54, HL 0.92-1.17, HW 0.97-1.34, C I 103-116, SL 0.94-1.18, SI 88-100, EL 0.17-0.24; PW 0.56-0.74, AL 0.88- 1.08, PPW 0.24-0.31, PPL 0.22-0.28, PPI 104- 122 (n = 40).

Mandibles usually smooth and shining, except for some small hair pits. Masticatory margin of mandible with three teeth arranged as an apical + a preapical + a long diastema + a somewhat truncated basal tooth. Basal margin of mandible lacking a curved lobe or tooth. Clypeus with a median longitudinal carina. Anterior clypeal margin usually with three strong teeth: a median tooth and one on each side, but sometimes the median tooth weak or vestigial. Ventral surface of clypeus usually with a short transverse carina. Palp formula 2,2. Frontal carinae not or just extending to the level of the posterior margins of the eyes. Antennal scrobes absent. Frontal lobes nearly completely absent; thus, the antennal articulations are almost entirely exposed. Antennal scapes, laid on the dorsal head, slightly surpassing the occipital margin. Eyes usually containing eight to nine ommatidia in the longest row. Pronotal spines varying in length from 0.12 to 0.28. Propodeal spines (ca. 0.18-0.28) equal to or slightly longer than the pronotal spines. Metapleural lobes small, usually triangular. Petiole node in profile with a long anterior peduncle; its anterodorsal angle is on a higher level than the posterodorsal; sometimes posterodorsal angle indistinct, showing a single curved surface. Postpetiole in dorsal view slightly broader than long and broadening from front to back. Dorsum of head smooth and shining. Dorsum of alitrunk smooth, but with a transverse ridge present at the approximate position of metanotal groove. Petiole, postpetiole, and gaster smooth and shining. Dorsal surfaces of head and alitrunk with numerous erect or suberect long hairs. A pair of long hairs bilaterally distributed on the dorsum of petiole node and on the postpetiole, respectively; sometimes the crests of both petiole node and postpetiole with additional one to two pairs of short hairs. First gastral tergite lacking erect or suberect hairs. Usually, three pairs of forward-projecting hairs present near the anterior clypeal margin. Scapes and tibiae with some erect to suberect short hairs. Color: head deep reddish-brown; alitrunk, pedicel segments, and gaster yellow-brown to reddish-brown.

Queen

Wang (2003) - Ergatoid. TL 4.06, HL l.08, HW l.16, CI 107, SL l.06, SI 91 , EL 0.21, PW 0.68, AL l.06, PSL1 0.18, PSL2 0.25, PPW 0.28, PPL 0.26, PPI 108 (n = l. Note : This is a paratype).

Similar to worker; color and pilosity as in worker, but head with three ocelli and promesonotum convex. Flight sclerites and wings lacking, but a black speck is present on each lateral margin of the mesonotum.

Queen. TL 4.62- 5.06, HL l.09-l.28, HW l.18-l.42, CI 107-115, SL l.06-l.20, SI 82-90, EL 0.22- 0.28, PW 0.80-0.90, AL l.14-l.34, PPW 0.30-0.36, PPL 0.26-0.30, PPI 107-133 (n = 5 ).

General shape with normal caste differences from the conspecific worker; a pair of acute minute spines present on the humeral angles of the pronotum; propodeal spines rather long, ca. 0.20 to 0.24; other characters similar to worker.

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 48, figs. 11-13, pl. 3 (worker, queen described))
  • Wang, M. 2003. A Monographic Revision of the Ant Genus Pristomyrmex (Hymenoptera:Formicidae). Bull. Mus. Comp. Zool. 157(6): 383-542 (page 478, figs. 187-192 worker, ergatoid queen, queen described)