Strumigenys impidora

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

Pyramica impidora casent0102547 profile 1.jpg

Pyramica impidora casent0102547 dorsal 1.jpg

Specimen labels

Known from a single type collection taken from a dead trunk in primary forest.

Identification

Bolton (2000) - Characters of chyatha-complex. Dorsum of clypeus and of head behind clypeus without standing hairs and without suborbicular hairs. Head conspicuously dorsoventrally flattened. Dorsal surfaces of alitrunk, waist segments and first gastral tergite without standing hairs.

Bolton (1983) – The flattened head and lack of specialized pilosity isolate impidora from the other members of the emarginata-group. The closest related species is Strumigenys chyatha, but here the dorsum of the head retains a transverse band of suborbicular hairs between the vertex and the occipital margin. In Strumigenys behasyla, another close species, two such bands of hairs are present, one occipitally and one just behind the frontal lobes, and the head is by no means as strongly dorsoventrally flattened.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Ivory Coast (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.

  • impidora. Smithistruma impidora Bolton, 1983: 294, fig. 6 (w.) IVORY COAST. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 121. See also: Bolton, 2000: 303.

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 2.1, HL 0.64, HW 0.40, CI 63, ML 0.06. MI 9, SL 0.25, SI 63, PW 0.25, AL 0.58.

Mandibles equipped with 5 relatively large teeth following the basal lamella (which is concealed by the clypeus). Distal to these are two slightly smaller teeth followed by 4 minute denticles and a small apical tooth. Anterior clypeal margin broadly and evenly concave, equipped with a series of 7 scale-like hairs which project forward over the mandibles. Of these the three central hairs are the smallest and the outermost pair, almost at the anterolateral angles, are by far the largest and form a transition to the fringe of large spatulate to spoon-shaped projecting hairs which line the lateral clypeal margins. Dorsum of clypeus and cephalic dorsum devoid of hairs of any description; upper scrobe margins and sides of head posteriorly devoid of hairs of any description. The cephalic dorsum and clypeal dorsum with scattered minute pubescence which is only visible at high magnification. Sides of clypeus shallowly convex and convergent anteriorly in full-face view. Preocular laminae slightly divergent anteriorly in full-face view. Antennal scapes broad and flattened, bent very close to the base and broadest at the level of the bend or just distal to it. Leading edges of scapes evenly rounded at the bend and with a series of projecting large spatulate hairs. Cephalic dorsum finely punctulate-granular everywhere, the clypeus shagreened. Head in profile very obviously dorsoventrally flattened, the ventrolateral margin of the head almost flat and the mid-posteroventral convexity of the head vestigial. Eyes of moderate size, the maximum diameter about 0.13 X HW, less than the maximum width of the scape. Pronotum not marginate laterally, without a median longitudinal ridge or carina dorsally. With alitrunk in profile the mesonotum and propodeum forming a single almost flat surface, without trace of metanotal groove. Propodeal teeth only slightly elevated from the line of the mesonotal-propodeal dorsa, somewhat upcurved along their length. Infradental lamellae vestigial, merely a minute crest between the propodeal teeth and the metapleural lobes. Dorsal alitrunk and dorsal surfaces of petiole, postpetiole and first gastral tergite lacking standing hairs of any description. The alitrunk and first gastral tergite only with minute appressed pubescence but the petiole and postpetiole bordered posteriorly by a sparse row of indistinct appressed hairs which project backward over the posterior spongiform appendages of the segments. Pronotal dorsum exceedingly feebly sculptured with vestiges of low minute longitudinal rugulae which are almost completely effaced. Mesonotum and propodeal dorsum smooth. Dorsum of petiole node shagreened, postpetiolar disc smooth. First gastral tergite unsculptured except for the feeble and widely spaced basigastral costulae. Sides of alitrunk mostly smooth but with punctures on the mesopleuron and sides of the propodeum. Spongiform appendages of pedicel segments massively developed in profile. In dorsal view the posterior border of the petiole node with a transverse spongiform strip which continues down the sides. Anterior margin of postpetiole shallowly concave and with a transverse spongiform strip, the posterior margin convex at the sides but flattened or slightly indented medially and with a transverse spongiform strip which is narrowed centrally. Sides of postpetiole disc with the more ventrally situated spongiform material projecting beyond the outline and visible in dorsal view; the spongiform tissue outline diverging from front to back. Base of first gastral tergite with a transverse spongiform band which is overlapped by that on the postpetiole. Colour uniform light brown.

Paratypes. TL 2.1-2.2, HL 0.62-0.64, HW 0.39-0.40, CI 63, ML 0.06, MI 9-10, SL 0.25-0.26, SI 64-65, PW 0.24-0.25, AL 0.56-0.60 (2 measured).

As holotype but maximum diameter of eye 0.11-0.13 x HW.

Type Material

Holotype worker, Ivory Coast: Abidjan, Banco Nat. Park, primary forest, dead trunk, 3.iii.1977 (I. Lobi) (MNH). Paratypes. 2 workers with same data as holotype (The Natural History Museum; Museum of Comparative Zoology).

References