Pristomyrmex divisus

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

Nothing is known about the biology of Pristomyrmex divisus.

Identification

Wang (2003) - 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 head only with scattered foveolate punctures.

Its closest relative is Pristomyrmex pulcher; from Malaysia. The workers of two species share the following three characters that are not seen in the other three members of the punctatus group (Pristomyrmex punctatus, Pristomyrmex rigidus, and Pristomyrmex fossulatus): (1) lateral portions of clypeus, in front of the antennal fossae, developd, making the antennal fossae well behind the anterior clypeal margins; (2) anterior clypeal margin lacking distinct denticles; and (3) the median portion of clypeus not flat but somewhat concave. In the workers of P. punctatus, P. rigidus, and P. fossulatus, the anterior clypeal margin is equipped with five to seven denticles, and the lateral portions of clypeus in front of the antennal fossae are reduced to margins (in other words, the antennal fossae reach the lateral anterior margins of clypeus), and the median portion of clypeus is more or less flat.

The workers of P. divisus are easily separated from those of P. pulcher. The cephalic dorsum shows rugoreticulum in P. pulcher but scattered foveolate punctures in P. divisus; the frontal carinae do extend to the level of the posterior margins of eyes in P. pulcher but not so in P. divisus; a pronounced median longitudinal furrow is present on the dorsal surface of alitrunk in P. divisus but absent in P. pulcher.

A member of the Punctatus species group

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 9.3° to 9.3°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Indo-Australian Region: Philippines (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Explore Overview of Pristomyrmex 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


.	Owned by Museum of Comparative Zoology.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

divisus. Pristomyrmex divisus Wang, M. 2003: 404, figs. 83, 84 (w.) PHILIPPINES.

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 3.06, HL 0.76, HW 0.80, CI 105, SL 0.82, SI 103, EL 0.22, PW 0.56, AL 0.74. Paratypes, 35 workers.

Worker. TL 3.06-3.40, HL 0.72-0.82, HW 0.74-0.86, CI 98-111, SL 0.78-0.90, SI 98-110, EL 0.21-0.24, PW 0.53-0.64, AL 0.72-0.80, PPW 0.26-0.30, PPL 0.18-0.22, PPI 123-156 (n = 20).

Mandibles 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, truncated basal tooth (or two minute denticles). A weak minute prominence present about midway on the basal margin of mandible. Clypeus with a strong median longitudinal carina extending through the frontal area; on each side of the median clypeal carina, a few additional rugae are usually present. Anterior clypeal margin lacking denticles. Median portion of clypeus higher than frontal area; lateral portions of clypeus developed, not reduced to margins. Ventral surface of clypeus lacking any toothlike prominences but usually with a few rugae. Palp formula 5,3. Frontal carinae short, not extending to the level of the posterior margins of eyes. Antennal scrobes absent. Frontal lobes 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 8 to 10 ommatidia in the longest row. Dorsum of alitrunk in dorsal view marginated, more or less depressed, and usually with a deep longitudinal furrow at middle. Pronotum unarmed. Propodeal spines well developed, acute and long, much longer than the distance between their bases. Metapleural lobes small, dentiform, and acute. Petiole in profile with a long peduncle; dorsum of peduncle, together with the anterior face of petiole node, forming a long declivity that reaches the top of petiole node. Ventral surface of petiole lacking any process. Postpetiole in profile with a convex dorsum, in dorsal view somewhat transverse-rectangular and much broader than long. Dorsum of head with numerous large and shallow foveolate punctures; space between foveolae smooth; ventral head with denser foveolate punctures. Dorsal surface of alitrunk with reticulate rugae. Petiole always, and postpetiole usually, with a coarse longitudinal ridge on each side. In dorsal view, petiole node and postpetiole each usually bounded by a rim; dorsums of both petiole and postpetiole, except for rims, very smooth and polished. Gaster unsculptured. Dorsal surfaces of head and alitrunk with numerous erect to suberect short hairs. A pair of hairs present, respectively, near the top of both petiole node and postpetiole. First gastral tergite without hairs. Two or three pairs of long, forward-projecting hairs present near the anterior clypeal margin. Scapes and tibiae with some erect to suberect short hairs. Color uniform reddish-brown; appendages sometimes slightly lighter.

Type Material

Holotype Worker. (Museum of Comparative Zoology). Philippines: Dumaguete, 1949, J. W. Chapman. Paratypes. (MCZC, The Natural History Museum, Australian National Insect Collection, Musee d'Histoire Naturelle Genève). 18 workers with same data as holotype; 14 workers, Philippines: Dumaguete (J. W. Chapman); three workers, Philippines: Dumaguete, Silliman University, 9.v.1949 (Domingo Empeso).

Paratype, 3 workers, Dumaguete, Philippines, Chapman,J.W., ANIC32-015650, Australian National Insect Collection.

References

Wang, M. 2003. A Monographic Revision of the Ant Genus Pristomyrmex (Hymenoptera:Formicidae). Bulletin of the Museum of Comparative Zoology 157(6): 383-542 (page 404, figs. 83-84 worker described)

References based on Global Ant Biodiversity Informatics

Wang M. 2003. A Monographic Revision of the Ant Genus Pristomyrmex (Hymenoptera:Formicidae). Bulletin of the Museum of Comparative Zoology 157(6): 383-542.
Wang M. 2003. A monographic revision of the ant genus Pristomyrmex (Hymenoptera:Formicidae). Bulletin of the Museum of Comparative Zoology 157(6):383-542