Strumigenys quadrua

Identification
Bolton (2000) - A member of the Strumigenys silvestrii-group. Despite the fact that both specimens are poorly mounted and have apparently suffered some abrasion, quadrua is easily recognised because of its 4-segmented antennae and extremely reduced preapical dentition. A few specimens of species in this group may show an apparently 5-segmented antenna, caused by the partial fusion of funicular segments 2 and 3, but in these individuals the fusion segment remains conspicuous, and they have at least one distinct preapical tooth on the mandible.

In the Neotropical Strumigenys fauna only the tramp species emmae also has 4-segmented antennae. The characters given in the key and under the species-group diagnoses quickly differentiate Strumigenys emmae from quadrua.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  quadrua. Strumigenys quadrua Bolton, 2000: 557 (w.) BRAZIL.

Worker
Holotype. TL 1.5, HL 0.38, HW 0.30, CI 79, ML 0.19, MI 50, SL 0.21, SI 70, PW 0.21, AL 0.40. Preapical armament of mandible of two minute vestigial denticles at least on right mandible, one just proximal and the other just distal of the mandibular midlength; denticles only properly visible at high magnification and with correct lighting so that in effect the mandible apparently lacks preapical dentition. Antenna with only 4 segments. Scape with an obtuse but abrupt subbasal bend, the hairs on the leading edge that curve toward the base of the scape longer than the maximum width of the scape. Ground-pilosity of head inconspicuous, simple to very narrowly linear-spatulate. Apicoscrobal hair apparently absent but specimens poorly mounted so this hair may have been dislodged. Pronotal humeral hair weakly flagellate; hairs on first gastral tergite flagellate. Sides of alitrunk smooth. Ventral surface of petiole without spongiform tissue; lateral spongiform lobe of petiole vestigial, scarcely more expanded than the posterior collar. Lamella on propodeal declivity narrow, angulate basally but not dentiform. Petiole node in dorsal view broader than long; disc of postpetiole and first gastral tergite smooth. Basigastral costulae at maximum longer than disc of postpetiole.

Paratype. TL 1.5, HL 0.38, HW 0.31, CI 82, ML 0.18, MI 47, SL 0.20, SI 65, PW 0.21, AL 0.41.

Type Material
Holotype worker, Brazil: Bahia, Ilheus, CEPEC-area Zoolog., km. 22 Ilheus-ltab., x.1986, no. 30 (J. Delabie).

Paratype. 1 worker with same data as holotype.