Strumigenys terroni

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

Known from the holotype worker.

Identification

Bolton (2000) - A member of the Strumigenys terroni-group. A relatively large and distinctive species that is closely related to Strumigenys tethepa. The two species are separated as follows.

Strumigenys tethepa: Head extremely dorsoventrally flattened, maximum depth of head in profile only 0.36 X HW. Height of antennal scrobe above eye about half the vertical diameter of the eye. Pronotum marginate laterally and approximately transversely flat in dorsal view. Petiole dorsum as long as broad, its sides divergent posteriorly. Petiole and postpetiole with standing hairs conspicuous on their dorsal surfaces. First gastral tergite with standing hairs distributed all over its surface. Larger species, TL 3.4-3.6, HW 0.66-0.68; scapes shorter, SI 55-56.

S. terroni: Head not remarkably flattened, maximum depth of head in profile 0.63 X HW. Height of antennal scrobe above eye about equal to the vertical diameter of the eye. Pronotum not marginate laterally, transversely evenly convex in dorsal view. Petiole dorsum broader than long, its sides weakly convex. Petiole and postpetiole with an inconspicuous row of spatulate hairs on each posterior margin that projects backwards over the spongiform collars. First gastral tergite without standing hairs. Smaller species, TL 2.5-2.6, HW 0.49-0.51; scapes longer, SI 62-63.

Bolton (1983) - The unique construction of the mandible immediately separates terroni from all its Afrotropical congeners.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun (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.

  • terroni. Smithistruma terroni Bolton, 1983: 299, fig. 7 (w.) CAMEROUN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 129. See also: Bolton, 2000: 327.

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 2·6, HL 0.74, HW 0.51, CI 69, ML 0.14, MI 19, SL 0.32, SI 63, PW 0.32, AL 0.76.

Mandibles narrowly triangular, with a distinct diastema separating the basal lamella (concealed by the clypeus but visible in anterior view) from the basalmost tooth, the length of the diastema conspicuously much greater than the height of the basalmost tooth. Counting from the base the mandibles with 6 relatively small teeth followed by a much larger seventh tooth, this tooth by far the largest on the masticatory margin and more than twice larger than those proximal to it. Of the row of six teeth preceding the enlarged seventh the first, third and fifth are larger than the second and fourth, the sixth is slightly smaller than the fifth but slightly larger than the fourth. The large seventh tooth is followed distally by 3 small teeth, a larger tooth, 4 minute denticles and a small apical tooth, making a total of 16 teeth altogether. Both mandibles similarly armed in the halo type but in one of the para types the left mandible has an additional minute denticle between the third and fourth tooth from the base, and this mandible thus has a total of 17 teeth. Anterior clypeal margin shallowly concave, with a series of 8 short scale-like hairs which are truncated apically; the outermost pair the largest. Anterolateral angles of clypeus rounded, with medially curved spoon-shaped hairs, the sides of the clypeus divergent posteriorly and with larger anteriorly curved spoon-shaped hairs. In full-face view the preocular laminae divergent anteriorly, the upper scrobe margins divergent posteriorly, the lateral margins of the occipital lobes evenly convex and the occipital margin deeply but evenly concave. Upper scrobe margins just behind the frontal lobes shallowly depressed on each side of a central higher area. Antennal scapes bent near base, flattened and broadest just distal to the bend, the leading edges with a row of freely projecting long spatulate to spoon-shaped hairs. Entire dorsum of head densely punctate. Ground-pilosity everywhere of minute decumbent to appressed stubble-like hairs, without standing pilosity of any description on the cephalic dorsum and without flagellate hairs. Eye moderate in size, with more than 15 ommatidia. Pronotum marginate anteriorly, the alitrunk without lateral margination but the propodeal dorsum separated from the sides by bluntly rounded angles. In dorsal view the pronotum without a median longitudinal ridge or carina and the metanotal groove absent. In profile the mesonorum shallowly convex, confluent with the shallowly sloping surface of the pronotum anteriorly but sloping more steeply posteriorly. The posterior half of the mesonotum forming a single surface with the propodeal dorsum. Propodeal teeth strong and stout, the infradental lamella vestigial and represented only by a narrow rim down the concavity of the declivity below the propodeal teeth. Sides of alitrunk mostly with scattered quite sharply defined relatively large punctures, the spaces between which are smooth, but the anterior portion of the mesopleuron finely reticulate-punctate, the punctures much smaller than elsewhere. Dorsal alitrunk with scattered punctures, the pronotum also with vestiges of exceptionally fine rugulae. Dorsal alitrunk only with scattered minute appressed hairs, without standing pilosity of any description and lacking flagellate hairs. Pedicel segments in profile with spongiform appendages massively developed. Dorsum of petiole node sculptured with strong scattered punctures and bordered posteriorly by a continuous transverse spongiform strip which is densest posterolaterally. Postpetiole in dorsal view with the disc smooth and unsculptured, completely surrounded by dense spongiform material. Posterior transverse spongiform strip of postpetiole feebly sinuate medially but not distinctly indented. Base of first gastral tergite with a narrow but dense transverse spongiform strip. Basigastral costula: narrow and sharply defined, not traversmg the basal spongiform tissue. Pedicel segments and gaster without standing pilosty, with minute appressed ground-pilosity and the posterior margins of the petiole and postpetiole with 1-2 pairs of larger appressed spatulate hairs which project backwards over the spongiform strips. Colour black.

Paratypes. TL 2.5-2.6, HL 0.72-0.74, HW 0.49-0.51, CI 68-69, ML 0.13-0.14, MI 18-19, SL 0.31-0.32, SI 62-63, PW 0.32-0.33, AL 0.74-0.78 (3 measured).

As holotype but with 7-8 short hairs bordering the concave anterior clypeal margin and one paratype with an extra mandibular tooth as discussed above.

Type Material

Holotype worker, Cameroun: nr Yaounde, sample 1911 (G. Terron) (Ecole Nationale Superieure Agronomique). Paratypes. 4 workers with same data as holotype (ENSA; The Natural History Museum).

References

  • Baroni Urbani, C. 1994b. [Untitled. Strumigenys schleeorum Baroni Urbani n. sp.] Pp. 35-38 in: Baroni Urbani, C., De Andrade, M. L. First description of fossil Dacetini ants with a critical analysis of the current classification of the tribe (Amber Coll (page 38, combination in Strumigenys)
  • 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). Bulletin of the British Museum (Natural History). Entomology. 46:267-416. PDF (page 299, fig. 7 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. Memoirs of the American Entomological Institute. 65:1-1028. (page 327, redescription of worker)