Strumigenys enkara

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

Pyramica enkara casent0102543 profile 1.jpg

Pyramica enkara casent0102543 dorsal 1.jpg

Specimen labels

The type material was collected from a dead tree trunk in a primary forest. Subsequent collections have been made in a number of forest habitats from litter collections.

Identification

Bolton (2000) - A member of the Strumigenys weberi-group. Disc of postpetiole coarsely longitudinally costulate, not swollen, in dorsal view surrounded by spongiform tissue. Head much broader than in Strumigenys minkara. Petiole node with spongiform posterior collar. Clypeus posteriorly without a transverse row of 4 almost vertical long stout hairs.

In specimens from Ghana the basal mandibular tooth is very small, the second tooth distinctly larger and the third tooth from the base is the longest. In material from Gabon the tiny basal most tooth has apparently been lost so that the longest tooth is the second from the base. For the present I am not treating this as significant at species rank.

Bolton (1983) - The five specimens constituting the non-paratypic material are very close to the holotype but have some minor differences. Principal among these is a rugulose propodeal dorsum, not seen in the type-series.

Of the three species in this group which possess a sculptured postpetiolar disc, Strumigenys minkara is easily differentiated by its very long narrow head, CI 54-58 as opposed to CI 63-68 in enkara and Strumigenys nykara. These last two species are differentiated by the characters given in the key plus the fact that nykara has long stout evenly curved clypeal hairs as well as the finer pilosity, such long hairs being absent in enkara. With the pedicel segments in profile the lateral spongiform appendage of the postpetiole touches or is confluent with the transverse strip bordering the anterior postpetiolar margin in enkara; in nykara there is a distinct gap between them.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun, Ghana, Ivory Coast (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.

  • enkara. Smithistruma enkara Bolton, 1983: 301, fig. 15 (w.) IVORY COAST. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 119. See also: Bolton, 2000: 337.

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 0.63, HW 0.41, CI 65, ML 0.08, MI 13, SL 0.28, SI 68, PW 0.28, AL 0.62.

Dentition as described for minkara but basal lamella of mandible (from non-paratypic material) a high truncated rectangle with concave sides; a small diastema present between the basal lamella and the basalmost tooth. Anterior clypeal margin transverse, the anterolateral angles of the clypeus rounded and the sides slightly convergent anteriorly. Lateral margins of clypeus with numerous projecting curved to flagellate simple fine hairs which are also present bordering the sides of the head. Dorsal surface of clypeus and dorsal surface of head with abundant fine simple hairs which are irregular to flagellate and mostly arched over so that the apices of most of them are directed back down towards the surface or are roughly parallel with the surface. All the cephalic hairs are fine and simple, without erect to suberect longer stouter straight hairs pointing up from the dorsum. Entire dorsum of head strongly reticulate-rugulose. Antennal scapes only very feebly bent at about the basal third, broadest at about the midlength, the leading edges arched convex and equipped with projecting simple hairs similar to those on the cephalic dorsum. Maximum diameter of eye 0.12 X HW. With the alitrunk in profile the mesonotum slightly elevated, the metanotal groove not impressed. Sides of pronotum not sharply marginate and the dorsum lacking a median longitudinal ridge or carina. Propodeal teeth narrow and acute, subtended by a vestigial infradental lamella. Pronotum, mesonotum, petiole, postpetiole and gastral tergites with numerous fine simple flagellate hairs, many of which are arched over towards the surface, as on the head. Sides of pronotum rugose, pleurae and sides of propodeum punctate. Pronotal dorsum densely coarsely longitudinally rugose, with a few cross-meshes; spaces between the rugae mostly narrow and smooth. Mesonotum with irregular strong rugae the spaces between which are punctate. Propodeal dorsum punctate, the declivity smooth. Petiole node irregularly but strongly rugose dorsally, the postpetiolar disc strongly longitudinally costulate-rugose. Basigastral costulae dense and strongly developed, extending almost the length of the sclerite centrally, less extensive on the sides. Spongiform appendages of pedicel segments massively developed in profile. In dorsal view the posterior margin of the petiole node with a broad spongiform strip whose posterior border is concave medially and which is broadest posterolaterally where it forms a rounded lobe. Postpetiole in dorsal view with the disc completely surrounded by thick spongiform material which is broadest posterolaterally and has the posterior strip indented medially. First gastral tergite with a broad spongiform band basally which is overlapped by the posterior spongiform strip of the postpetiole. Colour dark brown, the gaster blackish brown.

Paratype. TL 2.4, HL 0.63, HW 0.40, CI 63, ML 0.07, MI 11, SL 0.28, SI 70, PW 0.28, AL 0.62.

As holotype but maximum diameter of eye 0.13 X HW.

Bolton (2000) - TL 2.1-2.4, HL 0.58-0.66, HW 0.38-0.43, CI 63-68, ML 0.06-0.08, MI 10-13, SL 0.27-0.30, SI 68-74, PW 0.26-0.30, AL 0.56-0.65 (10 measured).

Type Material

Holotype worker, Ivory Coast: Abidjan, Banco Nat. Pk., primary forest, 3.iii.1977, in dead trunk (I. Lobl) (Musee d'Histoire Naturelle Genève). Paratype. 1 worker with same data as holotype (The Natural History Museum).

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. 1983. The Afrotropical dacetine ants (Formicidae). Bull. Br. Mus. (Nat. Hist.) Entomol. 46:267-416. PDF (page 301, fig. 15 worker described)
  • Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). J. Nat. Hist. 3 33: 1639-1689 (page 1673, combination in Pyramica)
  • Bolton, B. 2000. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028 (page 337, redescription of worker)