Strumigenys behasyla

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Strumigenys behasyla
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. behasyla
Binomial name
Strumigenys behasyla
(Bolton, 1983)

Strumigenys behasyla casent0900074 p 1 high.jpg

Strumigenys behasyla casent0900074 d 1 high.jpg

Specimen Labels

Specimens have been collected from rainforest litter samples.

Identification

Bolton (2000) - A member of the chyatha complex in the Strumigenys emarginata group. Characters of chyatha-complex. Cephalic dorsum in full-face view with two transverse bands of small suborbicular hairs. Anterior band consists of 2-3 transverse rows immediately behind the clypeus and frontal lobes, posterior band consists of 3 rows immediately in front of occipital margin ; vertex between the two bands without such hairs, this cephalic pilosity unique in the group. Dorsal surfaces of head and alitrunk without standing hairs of any form; first gastral tergite with one pair basally and one pair apically.

Bolton (1983) - In the emarginata-group four out of the five members of the chyatha-complex have broadly scale-like to suborbicular hairs on the head. In Strumigenys cavinasis and Strumigenys sharra such hairs are evenly distributed over the surface. In Strumigenys chyatha the hairs are restricted to a single transverse band just in front of the occipital margin, but in behasyla they are arranged in two transverse bands, one close to the occiput as in chyatha and another situated just behind the level of the frontal lobes.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun (type locality), Gabon.


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.

  • behasyla. Smithistruma behasyla Bolton, 1983: 286, fig. 4 (w.) CAMEROUN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 116. See also: Bolton, 2000: 300.

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 2.5, HL 0.67, HW 0.42, CI 63, ML 0.11, MI 16, SL 0.28, SI 67, PW 0.27, AL 0.68.

Mandibular dentition as described for cavinasis. Anterior clypeal margin very shallowly evenly concave, equipped with a row of broad short flattened hairs which project forward over the mandibles. Anterolateral clypeal angles rounded, the sides feebly divergent posteriorly and with a continuous row of anteriorly curved large spatulate to spoon-shaped hairs. In full-face view the preocular laminae feebly convergent posteriorly. Upper scrobe margins divergent posteriorly and with a row of anteriorly directed scale-like to broadly spoon-shaped hairs which are strongly curved. Occipital margin deeply evenly concave. Clypeal dorsum in full-face view with minute appressed stubble-like ground-pilosity, the individual hairs widely scattered. Cephalic dorsum just behind the level of the frontal lobes with a transverse band of broadly scale-like to suborbicular hairs. Behind this band the head only with stubble-like ground-pilosity like that on the clypeus but the zone between the highest point of the vertex and the occipital margin with a second transverse band of broadly scale-like hairs. Dorsum of head without simple fine hairs, without flagellate hairs. Scape bent in the basal third, somewhat flattened and broadest just distal to the bend, the leading edge equipped with a row of freely projecting spatulate to narrowly spoon-shaped hairs, the longest of which occurs at the bend of the scape. Dorsum of head finely and densely punctate, with a granular appearance; clypeal dorsum similarly but less strongly sculptured. Anterior border of pronotum marginate, the sides not marginate and without a median longitudinal ridge or carina dorsally. Metanotal groove represented by a faint transverse line on the dorsum, not impressed. Outline of dorsal alitrunk in profile with the pronotum and anterior part of the mesonotum sloping upwards to the highest point, which is shallowly convex; the posterior portion of the mesonotum and the propodeum forming a single extremely shallowly concave surface which is weakly sloped posteriorly. Propodeal teeth triangular and acute, the infradental lamella represented only by a narrow concave crest down each side below the teeth. Sides of alitrunk weakly superficially punctate, densest on the mesopleuron, the metapleuron almost smooth. Pronotal dorsum with extremely fine superficial but quite dense scratch-like longitudinal striation and with a few scattered punctures. Mesonotum anteriorly sculptured as pronotum but posteriorly only weakly punctate. Propodeal dorsum almost smooth, with only the faintest vestiges of sculpture. Dorsal alitrunk without standing hairs, flagellate hairs or any form of specialized pilosity, only with sparse appressed minute ground-pilosity. Spongiform appendages of pedicel segments strongly developed in profile, the subpetiolar process curtain-like and with a deep indentation at about its midlength. Postpetiolar ventral appendage large and lobate. Dorsum of petiole node superficially very shallowly punctate, the posterior spongiform strip lamellate. Postpetiole dorsum smooth, its posterior spongiform strip broadly and shallowly indented medially. Basal spongiform strip of first gastral tergite narrow but dense, not traversed by the basigastral costulae, the latter, however, are sharply defined on the tergite behind the spongiform tissue. Petiole and postpetiole dorsally with appressed short very narrowly spatulate hairs, the posterior margms of each segment with one or two pairs of much larger spatulate hairs which project backwards over the spongiform material. First gastral tergite with fine appressed very sparse ground-pilosity, and with two pam of longer stout hairs. The first, basally situated pair are erect or nearly so, the second pair, situated close to the apical margin of the tergite, are subdecumbent. Colour light brown.

Paratype. TL 2.5, HL 0.67, HW 0.42, CI 63, ML 0.11, MI 16, SL 0.28, SI 67, PW 0.27, AL 0.68. As holotype.

Type Material

Holotype worker, Cameroun: nr Yaounde, sample 1768 (G. Terron) (Ecole Nationale Superieure Agronomique). Paratype. 1 worker with same data as holotype (The Natural History Museum).

References