Pristomyrmex coggii

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Pristomyrmex coggii
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Pristomyrmex
Species: P. coggii
Binomial name
Pristomyrmex coggii
Emery, 1897

Pristomyrmex coggii casent0281799 p 1 high.jpg

Pristomyrmex coggii casent0281799 d 1 high.jpg

Specimen Labels

This species occurs in rainforest and has been collected in litter samples and in rotten wood on the ground.

Identification

Wang (2003) - Worker. Masticatory margin of mandible lacking a diastema and possessing four teeth, of which the third tooth , counting from the apex, smallest; eyes with two to four ommatidia in the longest row; dorsal surface of head, except for the scrobal are as, with foveolate-reticulate sculpture; dorsum of petiole node in dorsal view about as long as broad or slightly broader than long; first gastral tergite with only a few hairs.

Pristomyrmex coggii is closely related to Pristomyrmex boltoni and Pristomyrmex longus. The three species occur in New Guinea. Characters separating P. coggii from P. boltoni are provided under the latter name. Pristomyrmex coggii differs from P. longus because the dorsum of the petiole node in dorsal view is about as long as broad or broader than long in the workers of P. coggii but longer than broad in P. longus.

Pristomyrmex coggii differs from Pristomyrmex obesus of Solomon Islands as follows: The workers of P. coggii possess only a few hairs on the first gastral tergite and have smaller eyes containing two to three, rarely four, ommatidia in the longest row. But in the workers of P. obesus, the entire first gastral tergite is evenly covered with erect or suberect hairs, and the eyes contain five to seven (rarely four) ommatidia in the longest row. Pristomyrmex coggii differ from Pristomyrmex simplex of New Guinea and the Philippines because the dorsum of the head between the frontal carinae bears foveolate-reticulate sculpture in the workers of P. coggii but only scattered foveolate punctures in P. simplex; in addition, the eyes usually contain five ommatidia in the longest row in the workers of P. simplex but usually two to three in P. coggii.

A member of the Levigatus species group

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea (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

Worker

Nomenclature

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

  • coggii. Pristomyrmex coggii Emery, 1897c: 584 (w.) NEW GUINEA. Wang, M. 2003: 495 (q.).

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 2.20-2.S6, HL 0.60-0.74, HW 0.60-0.76, CI 9S-104, SL 0.48-0.64, SI 74-S6, EL 0.05-0.09, PW 0.40-0.48, AL 0.60-0.77, PPW 0.16-0.20, PPL 0.12-0.17, PPI 118-133 (n = 20).

Mandibles usually smooth and shining but sometimes with a few superficial longitudinal rugae. A broad and short or strongly prominent tooth present about midway on the basal margin of mandible. Clypeus flat, its anterior margin sometimes with three dentides: a median denticle and one on each side, but sometimes the median denticle absent or weak so that only two teeth are present there. Frontal area concave, with a median carina that usually extends to the clypeus. Ventral center of clypeus lacking any rugae or prominences. Palp formula 1,3. Frontal carinae distinct, extending to the level of the posterior margins of eyes. Scrobal impressions smooth and shallow, present lateral to the frontal carinae. Frontal lobes weakly expanded so that the antennal articulations are almost completely exposed. Eyes small, usually with two to three, rarely four, ommatidia in the longest row. Occipital margin straight or feebly concave in full-face view. Pronotum unarmed. Propodeum with a pair of triangular short spines. Metapleural lobes rounded. Petiole node in profile high, with the anterodorsal angle higher than the posterodorsal, its anterior peduncle about as long as the node. In dorsal view, dorsum of petiole node subrounded, about as long as broad, or trans-oval, slightly broader than long. Subpetiole with a narrow, long, semitranslucent lamella. Postpetiole in profile rounded dorsally, in dorsal view somewhat transverse-rectangular and broader than long. Dorsum of head, except for the scrobal are as, with dense foveolate punctures that form foveolate-reticulate sculpture; sometimes the punctures are almost aligned so that it seems that the several longitudinal rugae appear between the frontal carinae. Dorsum of alitrunk with sparse foveolate punctures. Petiole, postpetiole, and gaster unsculptured, smooth, and shining. Dorsal surfaces of head and alitrunk with numerous erect to suberect hairs. Dorsal surfaces of petiole node and postpetiole usually with two pairs of hairs, respectively. A few hairs present on the base of the first gastral tergite. A few pairs of forward-projecting hairs present near the anterior clypeal margin. Scapes and tibiae with numerous erect to suberect short hairs. Color reddish-brown.

Queen

Wang (2003) - TL 2.94-3.16, HL 0.72- 0.78, HW 0.72-0.82, CI 100-105, SL 0.56-0.66, SI 77-83, EL 0.15-0.17, PW 0.55-0.64, AL 0.78-0.96, PPW 0.21-0.24, PPL 0.17-0.18, PPI 122-133 (n = 3).

Generally similar to worker, except for normal caste differences. In addition, foveolate punctures shallow on the mesonotum, propodeal armaments slightly shorter than those in con specific worker.

Type Material

Wang (2003) - Lectotype worker, New Guinea: Montes Hansemanni et Berlinhafen (Biro) (Museo Civico di Storia Naturale, Genoa), here designated, [examined].

References

  • Wang, M. 2003. A Monographic Revision of the Ant Genus Pristomyrmex (Hymenoptera:Formicidae). Bull. Mus. Comp. Zool. 157(6): 383-542 (page 493, figs. 205-208 worker queen described)