Pristomyrmex pulcher

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Pristomyrmex pulcher
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Pristomyrmex
Species: P. pulcher
Binomial name
Pristomyrmex pulcher
Wang, M., 2003

Pristomyrmex pulcher casent0901708 p 1 high.jpg

Pristomyrmex pulcher casent0901708 d 1 high.jpg

Specimen Labels

This species has been collected from a litter sample taken in primary forest.

Identification

Wang (2003) - Worker. Lateral portions of clypeus in front of antennal fossae, developed, not reduced to margins, so that the antennal fossae are placed well behind the anterior clypeal margin; dorsal surfaces of head and alitrunk, as well as the sides of pronotum, with well-developed coarse rugoreticulum.

Although P. pulcher, an Oriental species, is very similar, in appearance of the workers, to Pristomyrmex punctatus, the two species are in fact not closely related within the punctatus group. Pristomyrmex pulcher, together with Pristomyrmex divisus, constitutes a clade that is the sister group of the clade formed by the species Pristomyrmex rigidus and P. punctatus. The separation of the two clades is summarized under P. divisus. Additional characters separating the workers of P. pulcher from those of P. punctatus are as follows: P. pulcher - A broad, short tooth present on the basal margin of mandible. Dorsum of petiole node with only a pair of erect hairs. Leg bicolored, with femur and tibia light-yellow and tarsus reddish-brown. Sculpture on the dorsal surfaces of head and alitrunk, and the sides of petiole and postpetiole relatively coarse Propodeal spines shorter, more robust, and slightly bent basally. P. punctatus - Tooth of the basal margin absent or inconspicuous. Dorsum of petiole node with two or more pairs of hairs. Leg uniformly colored, light-red or reddish-brown. Sculpture on the dorsal surfaces of head and alitrunk, and the sides of petiole and postpetiole relatively fine. Propodeal spines relatively slender, and straight. The separation of P. pulcher from P. divisus is discussed under P. divisus.

A member of the Punctatus species group

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Malaysia (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

Only known from the worker caste.

Nomenclature

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

  • pulcher. Pristomyrmex pulcher Wang, M. 2003: 408, figs. 87, 88 (w.) WEST MALAYSIA.

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

Description

Worker

Holotype. TL 2.96, HL 0.76, HW 0.72, C1 95, SL 0.82, SI 114, EL 0.20, PW 0.53, AL 0.76.

TL 2.70-3.04, HL 0.70-0.77, HW 0.69-0.77, C1 95-100, SL 0.76-0.84, SI 103-114, EL 0.19-0.21, PW 0.50-0.54, AL 0.70-0.78, PPW 0.25-0.29, PPL 0.17-0.20, PP1 135-156 (11 = 11).

Mandibles usually with a few longitudinal rugae but smooth near the masticatory margin. Dentition of the masticatory margin of mandible: the strongest apical tooth + the second strongest preapical + a long diastema + a broad basal tooth usually fused by two small denticles. A broad-based triangular short tooth present about midway on the basal margin of the mandible. Clypeus with sculpture consisting of a strong median longitudinal carina, a transverse carina (sometimes curved or weak or broken), and a few additional short carinae. Anterior clypeal margin lacking distinct denticles. Lateral portions of clypeus, in front of antennal fossae, developed, not reduced to narrow margins. Ventral surface of clypeus usually with a somewhat "n" ruga that is sometimes interrupted at the middle. Palp formula 5,3. Frontal carinae strong, extending to the level of the posterior margins of eyes. Slightly impressed scrobal areas present lateral to the frontal carinae. Frontal lobes nearly absent; thus, the antennal articulations are completely exposed. Antennal scapes, when lying on the dorsal head, surpassing the occipital margin of head by one-sixth to one-fifth of their length. Eyes large and prominent, containing seven to nine ommatidia in the longest row. Occipital margin straight or feebly concave. In dorsal view, dorsum of the alitrunk marginated and rather depressed. Pronotum unarmed. Propodeal spines well developed, acute, and long, much longer than the distance between their bases. Metapleural lobes triangular. Dorsum of petiole peduncle, together with the anterior face of the node, forming a long declivity that reaches the apex of the node. Ventral surface of petiole without any appendages or with only a very narrow rim. Postpetiole in profile convex dorsally, in dorsal view transverse-rectangular and much broader than long. Dorsal surfaces of head and alitrunk, as well as the sides of pronotum, with developed coarse rugoreticulum. Sides of the rest of the alitrunk irregularly rugulose. Antennal scapes with a few longitudinal rugae. Sides of both petiole and postpetiole usually with a few coarse longitudinal rugae. In dorsal view, petiole and postpetiole each bounded by a rim; dorsal surfaces of petiole and postpetiole, except for rims, very smooth and polished. Gaster unsculptured. Dorsal surfaces of head and alitrunk with numerous erect or suberect hairs. A pair of similar hairs present bilaterally near the top of petiole and two pairs usually on the dorsal postpetiole. Two or three pairs of long, forward-projecting hairs present near the anterior clypeal margin. Scapes and tibiae with some scattered erect or suberect hairs. Gaster lacking erect or suberect hairs. Femurs, tibiae light-yellow, in contrast with head, antennae, alitrunk, tarsi, pedicel segments, and gaster, which are reddish-brown.

Type Material

Holotype Worker: The Natural History Museum. Malaysia: Negri Sembilan, Pasoh For. Res., primaly forest, litter sample, 3.iv.1994 (L. Ficken). Paratypes, 11 workers (BMNH, Museum of Comparative Zoology, Australian National Insect Collection). Five workers with same data as holotype; three workers, Malaysia: Negri Sembilan, Pasoh For. Res., litter sample, 3.iv.1994 (M. Brendell, K. Jackson and L. Ficken); three workers, Malaysia: Neg. Sembilan, Pasoh For. Res., litter sample, xi.1994 (M. Brendell, K. Jackson, and S. Lewis).

References

  • Wang, M. 2003. A Monographic Revision of the Ant Genus Pristomyrmex (Hymenoptera:Formicidae). Bull. Mus. Comp. Zool. 157(6): 383-542 (page 408, figs. 87-88 worker described)