Strumigenys bellatrix

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

Specimens have been found in rainforest and secondary forest, with the collections being made from litter samples.

Identification

Bolton (2000) - A member of the Strumigenys weberi-group. S. bellatrix is related to Strumigenys malaplax and Strumigenys piliversa. The three species together are recognized by their possession of a smooth postpetiole disc, vestigial to absent metanotal groove and lack of stiff hairs on the cephalic dorsum that resemble those on the clypeal dorsum. The form of clypeal pilosity quickly separates the three as in bellatrix and piliversa there is a transverse row of 4 or 6 long erect hairs, the stoutest and longest of any dorsal surface, across the posterior margin of the clypeus. This row of setae effectively separates the stouter pilosity of the clypeus from the softer and more flexuous pilosity of the cephalic dorsum. Such a transverse row is absent in malaplax. In bellatrix the posterior clypeal row consists of 6 hairs that are relatively short, being shorter than the length of the clypeal dorsum when viewed in profile and only about 0.20 X HW. In pili versa on the other hand the posterior clypeal row consists of 4 hairs that are relatively very long, being at least equal to the length of the clypeal dorsum when viewed in profile and easily 0.50 X HW.

Keys including this Species

Key to Afrotropical Strumigenys (as Pyramica)

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 1.38333° to -0.317°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Afrotropical Region: Burundi (type locality), Kenya.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Explore Overview of Strumigenys 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.

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Castes

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

bellatrix. Pyramica bellatrix Bolton, 2000: 336 (w.) BURUNDI. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 116

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 2.4, HL 0.56, HW 0.43, CI 66, ML 0.07, MI 11, SL 0. 30, SI 70, PW 0.30, AL 0.64. With clypeus in full-face view the anterior margin evenly but extremely shallowly concave. Lateral margins of clypeus weakly convergent anteriorly and fringed with numerous anterolaterally projecting curved hairs. In oblique view across the clypeus these hairs are simple and blunted apically, they project outward from the margin and then bend sharply upwards in the apical third to half of their lengths. Clypeal dorsum with curved erect hairs that are slightly thickened or weakly clavate apically; the posterior clypeal margin with a transverse row of 6 much longer erect hairs that form a palisade between the clypeus and the remainder of the cephalic dorsum. Pilosity of lateral margins and dorsum of head, and that of promesonotum, waist segments and gaster entirely of soft fine flexuous hairs that are short-flagellate, wavy, or narrowly looped apically; all these hairs are finer, softer and more flexuous than those on the clypeus. Stiff simple hairs projecting from the leading edge of the scape curve upwards, or upwards and toward the scape base, in their apical portions. Dorsum of head coarsely but irregularly rugulose. Promesonotal dorsum coarsely irregularly rugose, the rugosity predominantly longitudinal. Dorsal surface of propodeum punctate, of petiole node longitudinally rugose; disc of postpetiole glassy smooth. First gastral tergite unsculptured except for a dense uninterrupted band of basigastral costulae.

Paratypes. TL 2.4-2.6, HL 0.64-0.68, HW 0.41-0.44, CI 64-66, ML 0.07-0.08, MI 11-12, SL 0.28-0.30, SI 67-70, PW 0.30-0.31, AL 0.64-0.66 (6 measured). As holotype but some paratypes with one or more hairs of the diagnostic posterior clypeal row abraded.

Type Material

Holotype worker, Burundi: Banage, 2.xi.1977 (A. Dejean) (The Natural History Museum).

Paratypes. 1 worker with same data as holotype; 5 workers with same data but 1.i.1977; 2 workers and 1 queen with same data but 1.xi.1977 (BMNH, Museum of Comparative Zoology).

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 336, worker described)

References based on Global Ant Biodiversity Informatics

Garcia F.H., Wiesel E. and Fischer G. 2013.The Ants of Kenya (Hymenoptera: Formicidae)Faunal Overview, First Species Checklist, Bibliography, Accounts for All Genera, and Discussion on Taxonomy and Zoogeography. Journal of East African Natural History, 101(2): 127-222
IZIKO South Africa Museum Collection
Ross S. R. P. J., F. Hita Garcia, G. Fischer, and M. K. Peters. 2018. Selective logging intensity in an East African rain forest predicts reductions in ant diversity. Biotropica 1-11.