Strumigenys bitheria

Strumigenys bitheria
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species:	S. bitheria
Binomial name
	Strumigenys bitheria; Bolton, 1983 Specimen Labels

Nothing is known about the biology of Strumigenys bitheria.

Identification

Bolton (1983, 2000) - A member of the nimbrata complex in the Strumigenys arnoldi-group. Closely related to Strumigenys nimbrata and sharing the striking reduction of the second and third funicular segments seen in that species, bitheria is distinguished by its broad lamellate upper scrobe margins, longer distal preapical teeth, stronger pronotal sculpture, longer narrower propodeal teeth, and by possessing a petiole node which is as long as broad in dorsal view.

Keys including this Species

Key to Afrotropical Strumigenys

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun (type locality).

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.

bitheria. Strumigenys bitheria Bolton, 1983: 367 (w.) CAMEROUN. See also: Bolton, 2000: 591.

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 1.9, HL 0.47, HW 0.37, CI 79, ML 0.20, MI 43, SL 0.28, SI 76, PW 0.22, AL 0.47.

Outer margins of mandibles very feebly convex in full-face view, broadest at about the level of the proximal preapical tooth and weakly tapering towards the base. Apical fork of 2 spiniform teeth, without intercalary teeth or denticles. Each mandible with 2 preapical teeth, the proximal of which is the largest and is situated Just distal of the midlength of the blade. The distance separating the bases of the pre apical teeth is less than the length of the distal preapical tooth. Anterior two-thirds of upper scrobe margins with a very conspicuous broad bordering translucent lamella or flange which is distinctly broader than the maximum diameter of the eye and approaches the maximum width of the scape. Eyes very small, with only 3-4 ommatidia, the maximum diameter of the eye distinctly less than the maximum width of the scape. Preocular notch absent, the ventral surface of the head without a transverse preocular groove or impression on each side. Antennal scapes narrow, slightly curved at the base and broadest at about the midlength, not distinctly flattened nor with the leading edges convex. Hairs fringing the leading edges of the scapes very slender, much smaller than those fringing the upper scrobe margins. Funicular segments 2 and 3 very reduced, vestigial, their combined length less than half that of the fourth (penultimate) funicular segment. Dorsum of head from posterior margin of clypeus to about the midlength densely clothed with broad conspicuous scale-like hairs. Behind this level mediodorsally are only much smaller sparse hairs but towards the sides of the occipital lobes are hairs similar in construction but smaller than those on the anterior half. Upper scrobe margins fringed with large anteriorly curved spoon-shaped hairs. Dorsum of head with 6 standing hairs arranged in a transverse row of 4 close to the occipital margin and a more anteriorly situated pair. Cephalic dorsum reticulate-punctate. Pronotal humeri each with a single fine flagellate hair. Mesonotum with a single pair of stout standing hairs. Ground-pilosity of dorsal alitrunk of small curved hairs. Posterior portion of mesonotum depressed behind the level of the standing hairs. Propodeal teeth triangular, elongate and narrow, longer than their basal width and subtended by narrow infradental lamellae. Sides of pronotum punctate, remainder of sides of alitrunk mostly smooth, with some punctate patches above and below a large smooth central area. Dorsal alitrunk reticulate-punctate, the pronotum also with some fine longitudinal rugulae. Petiole node as long as broad in dorsal view, the surface punctate. Postpetiole smooth. Spongiform appendages of pedicel segments poorly developed, the petiole with a narrow ventral strip and the node with a lateral lobe which is scarcely broader than the posterior collar. Ventral spongiform lobe of postpetiole about equal in size to the exposed area of the propodeal disc in profile. Basigastral costulae very short but stout, arising across the width of the tergite rather than on each side of a central clear area. Petiole, postpetiole and gaster with stout standing hairs which are swollen or thickened apically, colour light brown.

Type Material

Holotype worker, Cameroun: Nkoemvon, 2.iii.1980 (D. Jackson) (The Natural History Museum).

References

Bolton, B. 1983. The Afrotropical dacetine ants (Formicidae). Bulletin of the British Museum (Natural History). Entomology. 46:267-416. (page 367, worker described)
Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 591, redescription of worker)