Strumigenys aequinoctialis

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Strumigenys aequinoctialis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. aequinoctialis
Binomial name
Strumigenys aequinoctialis
De Andrade, 2007

Strumigenys aequinoctialis casent0905781 p 1 high.jpg

Strumigenys aequinoctialis casent0905781 d 1 high.jpg

Specimen Labels

Known from the Ecuadorian type material, collected from leaf litter.

Identification

Baroni Urbani & De Andrade (2007) - A member of the schulzi-group. Resembling Strumigenys umboceps but differing from it by its standing hairs much longer, by its propodeal spines longer, by its vertex with 4 longer, erect hairs, by its larger size and darker colour.

S. aequinoctialis and its closest relative, umboceps occupy an isolate position within the genus for their high-domed cephalic capsule. S. aequinoctialis is easily distinguished from umboceps for the four long hairs behind the highest point of the vertex. The two aequinoctialis specimens differ from the holotype unique of umboceps in the MCZC also for the presence of standing hairs on the mesosoma. Since there are differences in the number of hairs also between the aequinoctialis holotype and paratype, one cannot exclude that the umboceps unique had lost all its standing hairs during manipulation.

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Ecuador (type locality).


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • aequinoctialis. Strumigenys aequinoctialis De Andrade, in Baroni Urbani & De Andrade, 2007: 165, fig. 57 (w.) ECUADOR.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

TL 2.30-2.60; HL 0.62-0.72; HW 0.45-0.52; SL 0.31-0.36; ML 0.11-0.15; EL 0.06-0.09; WL 0.63-0.74; CI 72.2-72.6; SI 68.8-69.2; MI 17.7-20.8.

Head strongly converging anteriorly and with round vertexal corners. Head in profile with posterior half strongly tumuliform. Frontal lobes slightly expanded and convex. Antennal fossae ventrally with a carina visible in full-face view, straight, covering the lower margin of the scrobes and ending before the upper border of the eye. Eyes with 4-5 ommatidia in the longest row, placed over the ventral margin of the antennal scrobes. With the head in profile the scrobe is superficial, with the upper and lower margins weakly marked. Anterior clypeal margin broadly convex. Scapes slightly compressed dorsoventrally, with sub-basal bend, about half of the head length and surpassing the eyes posteriorly. Antennae with six segments. Apical funicular joint longer than the rest of the funiculus. Mandibles short, triangular. Basal tooth broad, subtriangular and followed by 11 teeth or denticles. Tooth 1 (basal), 2 and 3 the longest, sub equal in size, tooth 4 smaller than 1-3, tooth 5 slightly shorter than teeth 1-3, teeth 6-10 diminishing in size apically, apical tooth small but pointed.

Mesosoma in profile convex anteriorly and gently sloping posteriorly. Propodeal teeth pointed and subtended by a carina.

Petiole with node high and convex and with long peduncle. No spongiform processes on the petiole, except a very thin whitish carina on its posterior border. Postpetiole broadly convex, with developed spongiform processes ventrally. Anterior and posterior postpetiolar borders with a narrow spongiform crest, the crest broader posteriorly.

Gaster oval and with few, short costulae. Base of the first gastral tergite with narrow limbus. Base of the first gastral sternite with narrow spongiform pad.

Sculpture. Head, mesosoma and petiole reticulate-punctuate. Mesopleurae largely smooth. Postpetiole and gaster smooth and shining, except a few reticulations on the posterior half of the postpetiolar dorsum.

Pilosity. Head, meso soma and petiole with suberect or subdecumbent, spatulate hairs, slightly shorter on the clypeus, sparser on the mesosoma and rare on the petiole. Apicoscrobal hair absent. Cephalic dorsum with 4 long, erect hairs, slightly thicker on the apical half. Leading edge of the scapes with spatulate hairs curved basally and apically. Lateral clypeal margins with spatulate hairs curved anteriorly. Pronotal humeral hair present, long and weakly flagellate. Sides of the mesonotum with 1 erect, long, truncated, hair. Petiole, postpetiole, and gaster with erect-suberect, truncated hairs, rare on the petiole.

Colour. Holotype dark brown; paratype reddish brown with darker gaster.

Type Material

Holotype and paratype workers from Ecuador (Pichincha) labelled: km 38 road Calacali - La Independencia, 21.VIII.2004, 2000 m, leaf litter, C. Baroni Urbani & M. L. de Andrade (Museo Civico di Storia Naturale, Genoa).

Etymology

From the Latin aequinoctialis (=equinoctial), the closest concept to the Equator in Roman times

References