Pristomyrmex minusculus

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

This species occurs in rainforest and has been collected in litter samples, and in a rotting tree.

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; pronotum with a pair of teeth.

This species has a wide distribution in the Oriental region. It is also dispersed to North Queensland, Australia. Pristomyrmex minusculus must be derived from a P. levigatus-like ancestor. It is indistinguishable, in the queen, from Pristomyrmex levigatus at present. The workers of P. minusculus have almost same appearance as those of P. levigatus, except for a derived character-the pronotum with a pair of small teeth. In the levigatus group, this critical character is possessed only by the workers of P. minusculus, thus making them easily recognizable.

A member of the levigatus species group.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 9.516666412° to -15.933°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Australasian Region: Australia.
Indo-Australian Region: Indonesia, Micronesia (Federated States of), New Guinea, Palau, Tonga (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

Males have yet to be collected.

Nomenclature

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

minusculus. Pristomyrmex minusculus Wang, M. 2003: 507, figs. 229-232 (w.q.) PALAU IS (Peleliu I.).

Type Material

Holotype Worker. Museum of Comparative Zoology. Palau Is: Peleliu I., east coast, 26.i.1948 (H. S. Dybas). Paratypes, 16 workers and one queen (MCZC, Australian National Insect Collection, The Natural History Museum, NACA). Nine workers and one queen with same data as holotype; one worker, Wallis Is.: NukuTapu I., 28.iii.1965 to l.iv.1965 (G. Hunt). Two workers, Indonesia: Seram, above Haruru, near Masohi, 50 to 1.50 m, 18.iii.1981 (W. L. Brown); one worker, Indonesia: Irian Jaya, 12 km S of Sorong, forest fragment, l.v.1981 (W. L. Brown); two workers, Tonga Is.: Falehau, Niuatoputapu, moss + lichen, from coconut tree trunks, l.ix.1971 (W. and G. Rogers); two workers, YapGroup, vii-viii.50. (R. J. Goss).

Paratype, 3 workers, Peleliu I., Palau Islands, Palau Islands, Dybas,H.S., ANIC32-017624, Australian National Insect Collection.
Paratype, 1 worker, Tomil Dist., Yap Group, Micronesia, Goss,R.J., ANIC32-017625, Australian National Insect Collection.
Paratype, 1 worker, SYapID, Yap Group, Micronesia, Goss,R.J., ANIC32-017626, Australian National Insect Collection.
Paratype, 1 worker, Falehau, Niuatoputapu, Tonga, Rogers,W. & Rogers,G., ANIC32-017627, Australian National Insect Collection.
Paratype, 1 worker, Falehau, Niuatoputapu, Tonga, New Zealand Arthropod Collection.

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 3.02, HL 0.76, HW 0.80, CI 105, SL 0.66, SI 83, EL 0.14, PW 0.52, AL 0.78. Workers. TL 2.52-3.02, HL 0.66-0.78, HW 0.66-0.80, CI 99-106, SL 0.54-0.66, SI 77-84, EL 0.10-0.14, PW 0.45-0.52, AL 0.59-0.74, PPW 0.20-0.24, PPL 0.14-0.19, PPI 126-143 (n = 16).

Mandibles usually smooth and shining but sometimes with a few small shallow punctures. A broad-based short tooth present about midway on the basal margin of the mandible. Clypeus unsculptured. Anterior clypeal margin with a median tooth and two lateral teeth, but the median tooth often smaller than the others, sometimes the median tooth indistinct. Ventral surface of clypeus with a weak transverse ruga. Palp formula 1,3. Frontal carinae extending to the level of the posterior margins of the eyes. Scrobal areas shallow, short, present lateral to the frontal carinae in full-face view. Frontal lobes weakly expanded. Eyes moderately sized. Occipital margin feebly concave. Alitrunk in dorsal view more or less flat. Pronotum with a pair of acute small teeth; in some small specimens, this pair of teeth are very weak but visible, and in dorsal view they become a pair of sharp points on the two sides of the pronotum. Propodeum armed with a pair of spines, varying in length and shape, straight to slightly upcurved along their length. Metapleural lobes subtriangular, but rarely with a rounded apex. Petiole node in profile high with the anterodorsal angle higher than the posterodorsal, its anterior surface usually subparallel to the posterior one, its anterior peduncle about as long as the node. Subpetiole with a narrow rim. Postpetiole in profile high, rounded dorsally. Petiole node and postpetiole in dorsal view broader than long. Dorsum of head between the frontal carinae smooth and shining but sometimes with a few foveolate punctures bordering the frontal carinae, present on the genae and around the eyes. Dorsum of alitrunk smooth and shining. Petiole and postpetiole each with a lateral longitudinal ruga on each side that separates the tergite from the sternite. Gaster unsculptured. Dorsal surfaces of head and alitrunk with sparse erect to suberect hairs. Dorsal surfaces of petiole node and postpetiole each usually with two pairs of hairs and first gastral tergite with a few 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 yellow-brown to reddish-brown; appendages lighter.

Queen

TL 3.08, HL 0.72, HW 0.74, CI 103, SL 0.60, SI 81, EL 0.17, PW 0.60, AL 0.82, PPW 0.24, PPL 0.18, PPI 133 (n = 1).

Generally similar to worker, except for normal caste differences. In addition, pronotal armaments absent; propodeum with a pair of teeth or short spines that are shorter than those in the con specific worker.

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 507, figs. 229-232 worker, queen described)

References based on Global Ant Biodiversity Informatics

CSIRO Collection
Clouse R. M. 2007. The ants of Micronesia (Hymenoptera: Formicidae). Micronesica. 39: 171-295.
Clouse, R.M. 2007. The ants of Micronesia (Hymenoptera: Formicidae), Micronesica 39(2): 171-295.
Field Museum Collection, Chicago, Illinois (C. Moreau)
Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
Lucky A., L. E. Alonso, E. Sarnat, and J. Hulr. 2015. Ants and scolytine beetles. In: Richards, S.J. and N. Whitmore (editors) 2015. A rapid biodiversity assessment of Papua New Guinea's Hindenburg Wall region. Wildlife Conservation Society Papua New Guinea Program. Goroka, PNG.
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