Strumigenys anorbicula

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Strumigenys anorbicula
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. anorbicula
Binomial name
Strumigenys anorbicula
(Bolton, 2000)

Pyramica anorbicula casent0005649 profile 1.jpg

Pyramica anorbicula casent0005649 dorsal 1.jpg

Specimen labels

The type material was collected from sifted litter that consisted of leaf mold and rotten wood in a littoral rainforest.

Identification

Bolton (2000) - A member of the laticeps complex in the Strumigenys argiola group. Immediately diagnosed within the group by its lack of orbicular hairs anywhere on the head and presence of long fine hairs on the anterior clypeal margin, this species is also the only one known that has a transversely arched row of short erect hairs at the highest point of the vertex. See also notes under Strumigenys laticeps.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Gabon (type locality).


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Strumigenys were once thought to be rare. The development and increased use of litter sampling methods has led to the discovery of a tremendous diversity of species. Many species are specialized predators (e.g. see Strumigenys membranifera and Strumigenys louisianae). Collembola (springtails) and other tiny soil arthropods are typically favored prey. Species with long linear mandibles employ trap-jaws to sieze their stalked prey (see Dacetine trap-jaws). Larvae feed directly on insect prey brought to them by workers. Trophallaxis is rarely practiced. Most species live in the soil, leaf litter, decaying wood or opportunistically move into inhabitable cavities on or under the soil. Colonies are small, typically less than 100 individuals but in some species many hundreds. Moist warm habitats and micro-habitats are preferred. A few better known tramp and otherwise widely ranging species tolerate drier conditions. Foraging is often in the leaf litter and humus. Workers of many species rarely venture above ground or into exposed, open areas. Individuals are typically small, slow moving and cryptic in coloration. When disturbed individuals freeze and remain motionless. Males are not known for a large majority of species.

Castes

Worker

Queen

Nomenclature

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

  • anorbicula. Pyramica anorbicula Bolton, 2000: 287 (w.q.) GABON. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 115

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 2.2, HL 0.52, HW 0.64, CI 125, ML 0.26, MI 50, SL 0.26, SI 40, PW 0.38, AL 0.56. Apicodorsal tooth of mandible spiniform, much longer than the ventral tooth of the apical series; each apicodorsal tooth projects beyond the outer margin of the opposing mandible at full closure. Mandible with 2 small preapical teeth, located close to the apicodorsal tooth, the proximal preapical slightly longer than the distal. Mandible without large flattened hairs arising from its dorsal surface. Anterior clypeal margin with 6 very long anteriorly directed hairs that are not strap-like. Instead they are broadest basally, where they are somewhat flattened, but distally taper to long finely filiform apices; the longest of them (the outermost) are more than 0.50 X ML. Dorsum of head entirely lacking orbicular hairs. Highest point of vertex with an arched transverse row of short stout erect hairs that are inclined or feebly curved anteriorly. With alitrunk in profile outline of anterior portion of mesonotum slightly depressed, of posterior portion convex and humped.

Paratypes. TL 2.0-2.2, HL 0.48-0.54, HW 0.60-0.66, CI 122-129, ML 0.23-0.26, MI 46-50, SL 0.25-0.28, SI 39-43, PW 0.35-0.40, AL 0.54-0.58 (10 measured).

Type Material

Holotype worker, Gabon: Provo Estuaire, F. C. Mondah, 21 km. 331° NNW Libreville, 0°34.6'N, 9°20.1'E, 10 m., 24.ii.1998, #1742(10), sifted litter (leaf mold, rotten wood), littoral rainforest (B.L. Fisher) (The Natural History Museum).

Paratypes. 22 workers and 1 queen (dealate) with same data as holotype but sample numbers #1742 (2, 4, 6, 12, 13, 14, 15, 18, 44, and 45) (BMNH, Museum of Comparative Zoology, South African Museum, Los Angeles County Museum of Natural History, and in coll. Fisher).

References

  • Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria”. 99: 1-191.
  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 287, worker described)