Strumigenys obliqua

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

Strumigenys obliqua casent0900471 p 1 high.jpg

Strumigenys obliqua casent0900471 d 1 high.jpg

Specimen Labels

The type material was found in a forest, between old palm seed-pods.

Identification

Bolton (2000) - A member of the Strumigenys silvestrii-group. The oddly formed basigastral costulae, which occur in both queens as well as in the workers, are immediately diagnostic of this species.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Ecuador (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

Nomenclature

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

  • obliqua. Strumigenys obliqua Bolton, 2000: 555 (w.q.) ECUADOR.

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 1.7, HL 0.43, HW 0.34, CI 79, ML 0.24, MI 56, SL 0.28, SI 82, PW 0.25, AL 0.43. Preapical tooth of mandible separated from apicodorsal tooth by a distance greater than its own length. A tiny preapical denticle present that is very obviously proximal of mandibular midlength. Scape with an obtuse but conspicuous subbasal bend; curved hairs on leading edge of scape spatulate, the longest of them about equal to the maximum width of the scape. Apicoscrobal hair flagellate. Ground-pilosity of cephalic dorsum dense and narrowly spatulate, in profile elevated and strongly curved anteriorly. Close to occipital margin is a pair of slightly longer, more erect straighter hairs. Ground-pilosity of promesonotum not as dense as on head but also elevated, curved and very conspicuous. Pronotal humeral hair flagellate; an erect pair of hairs on the mesonotum. Hairs on first gastral tergite dense, in profile curved posteriorly; basal section of each hair slender, part or most of shaft distal of this somewhat flattened and expanded, shaft then narrowing again to an acute apical section. Similar hairs present on petiole and postpetiole. Second and third gastral tergites each with a pair of flagellate hairs. Propodeum with a pair of small teeth, subtended by narrow lamellae. Petiole in profile without spongiform tissue ventrally and without a lateral spongiform lobe; node with height of anterior face greater than length of dorsal surface (discounting posterior collar). In dorsal view petiole node broader than long. Disc of postpetiole mostly smooth. Basigastral costulae fine and dense, transverse to strongly oblique, present on at least basal half of the sclerite.

Paratype. TL 1.7, HL 0.44, HW 0.35, CI 80, ML 0.24, MI 55, SL 0.29, SI 83, PW 0.25, AL 0.44.

Type Material

Holotype worker, Ecuador: Sucua, 19.vii.1978, #798, no. 0890 (on underside of label) “in between old seed pods of palm, forest, some larvae may be in w/ Prionopelta” (G. J. Caphrey) (Museum of Comparative Zoology).

Paratypes. 1 worker and 2 alate queens with same data as holotype (MCZ, The Natural History Museum).

References

  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028.