Strumigenys ascita

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

Strumigenys ascita casent0900474 p 1 high.jpg

Strumigenys ascita casent0900474 d 1 high.jpg

Specimen Labels

Nothing is known about the biology of Strumigenys ascita.

Identification

Bolton (2000) - A member of the Strumigenys silvestrii-group. Among the minute species of the silvestrii-group ascita is the only one to have two spiniform preapical teeth on the mandible. A similar dentition is developed in the smilax-group but this is a much larger species that has many features isolating it from silvestrii-group members (compare group diagnoses).

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (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 Online Catalogue of the Ants of the World.

  • ascita. Strumigenys ascita Bolton, 2000: 550 (w.) BRAZIL.

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 1.8, HL 0.44, HW 0.34, CI 77, ML 0.30, MI 68, SL 0.30, SI 88, PW 0.22, AL 0.43. Mandible with 2 spiniform preapical teeth, the distal about two times longer than the proximal. Distal preapical tooth about as long as distance separating it from apicodorsal tooth; proximal tooth located just proximal of mandibular midlength. Eye of only 1-2 ommatidia. Scape with an obtuse but very conspicuous subbasal bend. Ground-pilosity of cephalic dorsum and dorsal alitrunk spoon-shaped and distinctive. Curved hairs on leading edge of scape spoon-shaped and stout, shorter than maximum width of scape. Apicoscrobal hair a very short stub of simple fine hair (may be broken remnant of longer hair). Cephalic dorsum with a pair of short erect hairs close to occipital margin. Pronotal humeral hair flagellate; standing hairs absent from mesonotum. First gastral tergite with numerous spatulate hairs that are subappressed and are directed medially or posteromedially; extreme apex of first tergite, and tergites 2 and 3, each with a few erect fine flagellate hairs. On dorsum of hind femur the gland bulla is distal of the midlength. Petiole node in dorsal view broader than long; ventral surface of petiole without spongiform tissue but lateral lobe developed and spongiform. Mesopleuron and metapleuron smooth. Disc of postpetioie reticulate-punctate. Basigastral costulae fine and numerous, longer at maximum than disc of postpetiole.

Paratype. TL 1.7, HL 0.45, HW 0.34, CI 76, ML 0.28, MI 62, SL 0.28, SI 83, PW 0.22, AL 0.44.

Type Material

Holotype worker, Brazil: Arnawnas, Manaus, Dirnona, 19.i.1994, #71 (R. Didham) (The Natural History Museum).

Paratype. 1 worker, Brazil: Macapa-Arnapa, Rod. Duque de Caixas, krn. 9, 19.x.1997, 78T (J. M. Vilhena) (Instituto Nacional de Pesquisas da Amazonia).

References

  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 550, worker described)

References based on Global Ant Biodiversity Informatics

  • Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65