Strumigenys laticeps

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Strumigenys laticeps
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. laticeps
Binomial name
Strumigenys laticeps
(Brown, 1962)

Strumigenys laticeps casent0900046 p 1 high.jpg

Strumigenys laticeps casent0900046 d 1 high.jpg

Specimen Labels

The type material was collected from the base of dead tree.

Identification

Bolton (2000) - A member of the laticeps complex in the Strumigenys argiola group. Four of the seven sub-Saharan species in this group were fully documented by Bolton (1983); all are easily distinguished by the characters given in the key. Strumigenys minima, apart from having only 4 antennal segments, is the only species to have well-defined lateral and ventral spongiform lobes on the postpetiole and is very small (HW < 0.35). The remaining species have 6 antennomeres and lack, or have only minute vestiges of, spongiform lobes.

In Strumigenys anorbicula, Strumigenys roomi and Strumigenys mormo the apicodorsal mandibular tooth is long and spiniform, very much longer than the apicoventral tooth of the apical vertical series. Of these three anorbicula lacks cephalic orbicular hairs and has the anteriorly projecting long hairs on the anterior clypeal margin filiform rather than strap-like. In both roomi and mormo orbicular hairs on the head and strap-like hairs on the anterior clypeal margin are conspicuous. S. roomi has only one preapical tooth on each mandible and the dorsum of the head immediately behind the clypeus lacks orbicular hairs, though such hairs do occur more posteriorly on the vertex. In mormo two preapical teeth are present and orbicular hairs occur on the cephalic dorsum from immediately behind the posterior clypeal margin.

The apicodorsal mandibular tooth is small in Strumigenys laticeps, Strumigenys marchosias and Strumigenys tiglath, at most only fractionally longer than the apicoventral tooth, and orbicular hairs occur on the head immediately behind the posterior clypeal margin. Of these three laticeps lacks large flattened hairs on the dorsal surfaces of the mandibular blades and the mesonotum is strongly swollen and humped posteriorly. S. marchosias and tiglath each have two large flattened hairs arising from the dorsal surface of each mandibular blade and the mesonotum is not humped. The former of these has two preapical teeth on each mandible and long strap-like clypeal hairs; the latter has only a single small preapical tooth and much shorter strap-like hairs.

Bolton (1983) - The closest relative of laticeps is Strumigenys tiglath, which shows most of the characters of laticeps including the 6-segmented antennae, lack of a spiniform tooth dorsally in the apical armament of the mandible, orbicular hairs which occur immediately behind the clypeus and vestigial spongiform appendages on the petiole and postpetiole. Features separating the two species are as follows.

laticeps tiglath
Larger species with longer mandibles, HW 0.46-0.59, MI 42-48. Smaller species with shorter mandibles, HW 0.39, MI 35.
Dorsal surfaces of mandibular blades lacking large flattened hairs. Dorsal surfaces of each mandibular blade with two large flattened hairs.
Subbasal lobe of scape broad and bluntly rounded. Subbasal lobe of scape narrow and narrowly rounded.
Mesonotum strongly swollen and humped posteriorly. Mesonotum not swollen, not humped posteriorly.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun, Gabon, Ghana, Ivory Coast, Nigeria (type locality), Uganda.
Malagasy Region: Madagascar.


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.

  • laticeps. Epitritus laticeps Brown, 1962b: 77, figs. 1-4 (w.) NIGERIA. Combination in Pyramica: Bolton, 1999: 1672; in Strumigenys: Baroni Urbani & De Andrade, 2007: 122. See also: Bolton, 1983: 355; Bolton, 2000: 289.

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

Description

Brown 1962. Figures 1-4.

Worker

Bolton (1983) - TL 1.7-2.2, HL 0.40-0.48, HW 0.46-0.59, CI 115-125, ML 0.18-0.22, MI 42-48, SL 0.22-0.29, SI 47-50, PW 0.26-0.32, AL 0.41-0.50 (12 measured).

Mandibular blades with a single pre apical denticle, situated close to the apex. Apical armament of mandible consisting of a series of 7-8 denticles, without a conspicuously elongate spiniform tooth at the dorsal end of the series. Dorsal surfaces of mandibular blades naked, without large flattened hairs arising from them. Anterior clypeal margin with 4 long strap-like spatulate hairs which project forwards, the outer pair longer than the inner; and also with a short spatulate hair close to the inner base of each mandibular blade. Clypeus shining, with numerous very small appressed spatulate hairs. Remainder of head finely densely reticulate-punctate and equipped with orbicular hairs which occur from the posterior clypeal margin to the occiput; without a large space behind the clypeus which is free of orbicular hairs. Antennae 6-segmented, the scapes strongly back-curved and with a large anteriorly directed subbasal lobe at the bend, the leading edge with a row of projecting large flattened to spoon-shaped hairs. Alitrunk in profile with the mesonotum strongly humped posteriorly, the highest point of the outline being at or just behind the mesonotal midlength. Anteriorly the mesonotum slopes down to its junction with the pronotum and posteriorly it joins the still more steeply sloped propodeal dorsum. Propodeal declivity bordered by a broad lamella, usually without teeth but rarely an angular tooth is developed, projecting posteriorly from the dorsal end of the lamella. Sides of alitrunk densely reticulate-punctate everywhere. In dorsal view the alitrunk with a very shallow and feeble impression between pronotum and mesonotum and with a distinct transverse line between mesonotum and propodeum, the entire surface densely reticulate-punctate. Alitrunk lacking bizarre pilosity but dorsally with scattered minute simple hairs. Petiole and postpetiole reticulate-punctate. In dorsal view both pedicel segments conspicuously broader than long, the postpetiole with a concave anterior face and a shallow median longitudinal impression. Spongiform appendages vestigial, reduced to a narrow posterior transverse strip on the petiole node, a similar but somewhat broader strip on the postpetiole and with a short strip on the anterior postpetiolar border which traverses the most concave part of the margin. In profile both segments lacking ventral spongiform appendages, the lateral appendage of the postpetiole very reduced and present only at the posterior angle. Dorsal surfaces of pedicel segments with minute hairs as on pronotum, the first gastral tergite with larger long strong hairs which are clavate apically; the surface of the tergite weakly reticulate-shagreened and with short feeble basal costulae. Colour medium brown.

Type Material

Bolton (1983) - Holotype and paratype workers, NIGERIA: nr Zungeru on the Kaduna road, 19.xii.1956, base of dead tree, S780 (W. A. Sands) (The Natural History Museum; Museum of Comparative Zoology; National Museum of Natural History) [examined].

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
  • Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). Journal of Natural History. 33:1639-1689. (page 1672, combination in Pyramica)
  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 289, figs. 198, 226 redescription of worker)
  • Brown, W. L., Jr. 1962b. A new ant of the genus Epitritus from south of the Sahara. Psyche. 69:77-80. (page 77, figs. 1-4 worker described)