Pristomyrmex cebuensis

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Pristomyrmex cebuensis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Pristomyrmex
Species: P. cebuensis
Binomial name
Pristomyrmex cebuensis
Zettel, 2007

Pristomyrmex cebuensis fig 02.jpg

Nothing is known about the biology of Pristomyrmex cebuensis.

Identification

Zettel (2007) - Large species, TL = 4.89-5.34. Clypeus on ventral surface with more or less developed transverse ridge or low tubercle, dorsally with prominent median carina and pair of fine but complete lateral rugae along sides, and on anterior margin with seven (rarely confluent to five or six) small denticles. Masticatory margin of mandible with four teeth and diastema. Pronotum with pair of very long spines (PSLl 0.52-0.62), which are more than four times as long as propodeal spines (PSL2 0.11-0.15). Dorsum of head between frontal carinae with large punctures, almost alveolate, lateral to frontal carinae and on genae with longitudinal rugae. Dorsum of alitrunk anteriorly smooth and polished, posteriorly with some longitudinal rugae. Frontal carinae posteriorly reaching level of posterior eye margin, antennal scrobes distinct. Anterior face of petiolar node distinct from dorsal surface of peduncle. Petiolar node with three to five pairs of hairs. First gastral tergite without erect setae.

This species is similar to Pristomyrmex curvulus Wang 2003. Important similarities are especially found in the structures of the clypeus, the punctured central dorsum of the head, the longitudinal rugae on genae and sides of alitrunk, and the long pronotal spines. However, there are several obvious differences between the two species: the dorsum of the head between the frontal carinae is finely and sparsely punctured in P. curvulus (see Alpert et al. 2007), but with coarse, almost alveolate punctures which are partly longitudinally confluent in P. cebuensis nov.sp. The clypeus of P. cebuensis has a pair of sharp lateral rugae along sides, while in P. curvulus only “sometimes a few additional superficial rugae” are present (Wang 2003). The mandible of P. cebuensis is finely and densely striate all over its surface, but in P. curvulus it is punctured and “with a few basal longitudinal rugae” (Wang 2003; see also Alpert et al. 2007). The pronotal spines are comparatively long in both species, but in P. cebuensis even longer than in P. curvulus, in absolute length (PSLl 0.52-0.62 vs. PSLl 0.38-0.44) as well as in relative length compared to propodeal spines (the pronotal spines in P. cebuensis are more than four times as long as the propodeal spines, but in P. curvulus approximately three times as long). Finally, the posterior dorsum of the alitrunk bears some rugae in P. cebuensis which are absent in P. curvulus. From the other two Philippine species with punctured head and long pronotal spines, Pristomyrmex longispinus from Negros and Pristomyrmex schoedli from Leyte, the new species can be readily distinguished - among other features - by the sharp median carina of the clypeus.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Philippines (type locality).

Distribution based on AntMaps

AntMapLegend.png

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

Nomenclature

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

  • cebuensis. Pristomyrmex cebuensis Zettel, 2007: 1252, figs. 1, 2 (w.) PHILIPPINES (Cebu I.)

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

Description

Worker

Measurements of holotype worker: TL 5.17, HL 1.24, HW 1.28, Cl 103, SL 1.42, SI 111, EL 0.23, PW 0.81, AL 1.30, PPW 0.34, PPL 0.39, PPI 87.

Measurements of paratype workers (n = 9): TL 4.89-5.34, HL 1.21-1.26, HW 1.21-1.32, CI 100-105, SL 1.38-1.44, SI 107-115, EL 0.22-0.24, PW 0.77-0.85, AL 1.29-1.40, PPW 0.33-0.36, PPL 0.35-0.40, PPI 105-111.

Head: Mandibles with fine longitudinal rugae, reduced, at most, at extreme dorsal apex. Masticatory margin of mandible with four teeth: strongest apical + second strongest preapical + long diastema + two small basal teeth of similar size; basal margin of mandible almost straight, lacking tooth. Clypeus short, with strong, sharp and complete median carina and one pair of fine, but sharp and complete rugae along sides. Anterior clypeus margin with short median tooth and three (rarely two) short lateral denticles on each side. Venter of clypeus with transverse ridge which is laterally reduced in some specimens; then the ridge appears as a low medial tubercle. Palp formula 1,3. Frontal carinae strongly developed, posteriorly extending caudad approximately to level of posterior eye margins. Antennal scrobes distinct, laterally delimited by short, sharp ridges. Frontal lobes absent; antennal insertion entirely exposed. Genae and lateral dorsum of head up to frontal carinae with more or less distinct longitudinal rugae. Frons anteriorly with median furrow. Antennal scapes, when lying on dorsum of head, clearly surpassing occipital margin of head. Eyes containing ca. 11-13 ommatidia in longest row. Pronotum with pair of long spines, PSLl 0.52-0.62. Propodeum with pair of short spines, 0.11-0.15, distinctly shorter than distance between apices. Dorsum of alitrunk somewhat flattened, behind pronotal spines almost straight in lateral view. Metapleural lobes triangular, with weakly rounded apex. Petiole in profile with long peduncle; peduncle distinct from anterior surface of node by shallow concavity; node almost evenly rounded in lateral view. Postpetiole in profile rounded dorsally, in dorsal view slightly broadening from front to back. Dorsum of head not rugoreticulate, but with relatively dense, large punctures, almost foveolate, punctures variably confluent longitudinally, interspaces smooth and polished. Scrobal areas with few longitudinal rugae. Dorsum of alitrunk smooth and polished, but in posterior part with a few more or less developed longitudinal rugae. Petiole, postpetiole, and gaster smooth and shiny. Dorsal surfaces of head and alitrunk with numerous long erect or sub erect hairs. Dorsum of petiolar node with 3-5 pairs of setae; dorsum of postpetiole with 2-4 pairs. First gastral tergite lacking erect or suberect hairs. A few pairs of forward projecting hairs present near anterior clypeal margin. Scapes and tibiae with numerous erect to suberect hairs. Colour reddish-brown.

Type Material

Holotype (worker; in the Entomological Collection of the University of San Carlos, Cebu City) and paratypes (nine workers; in the Natural History Museum Vienna and in the author's collection) labelled “Philippines: Cebu\ Cebu City, Cantipla-Uno\ 7.3.22007, leg. c.\ Pangantihon (P258)”. Type locality: Philippines, Cebu Island, municipality of Cebu City, barangay Tabunan, sitio Cantipla-I [= Cantipla-Uno], ca. 800-900 m a.s.l., 10°24' N, 123°49' E (GPS).

References