Psalidomyrmex

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Psalidomyrmex
Psalidomyrmex foveolatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Alliance: Plectroctena genus group
Genus: Psalidomyrmex
André, 1890
Type species
Psalidomyrmex foveolatus
Diversity
6 species
(Species Checklist)

Psalidomyrmex foveolatus casent0101471 profile 1.jpg

Psalidomyrmex foveolatus

Psalidomyrmex foveolatus casent0101471 dorsal 1.jpg

Specimen Label

A small genus (six described species) restricted to central and western Africa. They are cryptic foragers, and at least one species is a specialist predator of earthworms. The latest generic revision is by Bolton (1975b) and there is an updated list of species and a species key presented in Bolton & Brown (2002). Species of Psalidomyrmex nest in rotten wood, beneath logs, or directly in the ground and hunting is generally performed solitarily (Bolton, 1975b). All species seem to be specialised predators of earthworms. Workers are able to capture worms as long as 10 cm (Dejean et al., 1999).

Identification

Schmidt and Shattuck (2014) - Psalidomyrmex workers and queens are readily identified by their unique mandibular structure (mandibles falcate to subtriangular, with broadly rounded basal angles and an attenuated apical tooth) and by their projecting labral lobe, both of which are autapomorphic within the Ponerinae. Other diagnostic characters include the hypertrophied frontal lobes, longitudinal groove on the propodeal dorsum, and large lateral metapleural gland orifice. Psalidomyrmex is most similar to the other members of the Plectroctena genus group, including Loboponera and Plectroctena itself. In addition to lacking the two autapomorphies of Psalidomyrmex already mentioned, these genera differ from Psalidomyrmex in having longitudinal dorsal grooves in the meso- and metafemora and distinct propodeal lamellae.

Keys including this Genus

Keys to Species in this Genus

Distribution

Psalidomyrmex is restricted to central and western Africa, ranging from Sierra Leone to Kenya and as far south as Gabon and the Democratic Republic of Congo (Bolton, 1975b; Bolton & Brown, 2002).

Distribution and Richness based on AntMaps

Biology

Schmidt and Shattuck (2014) - Very little is known about the ecology and behavior of Psalidomyrmex. They nest in rotting logs, in the soil beneath rotting logs (Bolton, 1975b), or in deserted termitaries (Déjean et al., 1996, 1997), and workers forage individually in rotting wood or in leaf litter (Bolton, 1975b). Psalidomyrmex procerus is known to be a specialist predator of earthworms (Lévieux, 1982; Déjean et al., 1992), and though the feeding habits of the other species is unknown, it seems likely that they too may feed on earthworms, given the apparently specialized mandibular structure of the genus.

Castes

Morphology

Worker Morphology

 • Antennal segment count 12 • Antennal club gradual • Palp formula 3,4 • Total dental count 1-11(0-4) • Spur formula 1 pectinate, 1 pectinate • Sting present

Male Morphology

 • Antennal segment count 13 • Antennal club 0 • Palp formula 3,4 • Total dental count 0-1 • Spur formula 1 pectinate, 1 pectinate

Nomenclature

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

  • PSALIDOMYRMEX [Ponerinae: Ponerini]
    • Psalidomyrmex André, 1890: 313. Type-species: Psalidomyrmex foveolatus, by monotypy.

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

Description

Schmidt and Shattuck (2014):

Worker

Medium to large (TL 9.0–16.0 mm; Bolton, 1975b) ants with the standard characters of Ponerini. Mandibles falcate to subtriangular, with rounded basal angles, a long apical tooth and a basal groove. Labrum projecting anteriorly beyond the anterior clypeal margin as a lobe. Frontal lobes large, expanded laterally and closely approximated. Eyes of moderate size, located anterior to head midline. Metanotal groove vestigial. Propodeum broad dorsally, with a shallow longitudinal groove dorsally. Propodeal spiracles round. Metapleural gland orifice very large, opening laterally. Metatibial spur formula (1p). Petiole nodiform. Anteroventral articulatory surface of petiole long and broad, with a narrow median V-shaped longitudinal groove. Gaster with a strong constriction between A3 and A4. Head and body with moderate sculpturing (variously punctate, foveolate or striate), with very sparse pilosity and no pubescence. Color reddish brown to black.

Queen

Similar to workers but slightly larger, alate and with ocelli.

Male

See description in Bolton (1975b).

Larva

Described for Psalidomyrmex procerus by Wheeler & Wheeler (1964).

References

  • André, E. 1890. Matériaux pour servir à la faune myrmécologique de Sierra-Leone (Afrique occidentale). Rev. Entomol. (Caen) 9: 311-327 PDF (page 313, Psalidomyrmex as genus)
  • Ashmead, W. H. 1905c. A skeleton of a new arrangement of the families, subfamilies, tribes and genera of the ants, or the superfamily Formicoidea. Can. Entomol. 37: 381-384 (page 382, Psalidomyrmex in Pachycondylinae, Pachycondylini)
  • Bolton, B. 1975b. A revision of the African ponerine ant genus Psalidomyrmex André (Hymenoptera: Formicidae). Bull. Br. Mus. (Nat. Hist.) Entomol. 32: 1-16 (page 1, Revision of genus.)
  • Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 170, Psalidomyrmex in Ponerinae, Ponerini)
  • Dalla Torre, K. W. von. 1893. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Vol. 7. Formicidae (Heterogyna). Leipzig: W. Engelmann, 289 pp. (page 31, Psalidomyrmex in Ponerinae)
  • Emery, C. 1895l. Die Gattung Dorylus Fab. und die systematische Eintheilung der Formiciden. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 8: 685-778 (page 767, Psalidomyrmex in Ponerinae, Ponerini)
  • Emery, C. 1911e. Hymenoptera. Fam. Formicidae. Subfam. Ponerinae. Genera Insectorum 118: 1-125 (page 95, Psalidomyrmex in Ponerinae, Ponerini [subtribe Plectroctenini])
  • Forel, A. 1917. Cadre synoptique actuel de la faune universelle des fourmis. Bull. Soc. Vaudoise Sci. Nat. 51: 229-253 (page 238, Psalidomyrmex in Ponerinae, Ponerini)
  • Schmidt, C.A. & Shattuck, S.O. 2014. The higher classification of the ant subfamily Ponerinae (Hymenoptera: Formicidae), with a review of ponerine ecology and behavior. Zootaxa. 3817, 1–242 (doi:10.11646/zootaxa.3817.1.1)
  • Wheeler, W. M. 1910b. Ants: their structure, development and behavior. New York: Columbia University Press, xxv + 663 pp. (page 135, Psalidomyrmex in Ponerinae, Ponerini)
  • Wheeler, W. M. 1922i. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VII. Keys to the genera and subgenera of ants. Bull. Am. Mus. Nat. Hist. 45: 631-710 (page 650, Psalidomyrmex in Ponerinae, Ponerini)