Strumigenys silvestrii

Identification
Bolton (2000) - Within the silvestrii-group 6 species have pilosity on the first gastral tergite that is not predominantly or entirely of fine elongate or flagellate hairs. In these 6 the pilosity of the first gastral tergite is of spatulate, remiform or simple stiff hairs. One such species, Strumigenys ascita, has two narrowly spiniform preapical teeth on each mandible, as opposed to one tooth and a minute denticle in the remainder. Three species of Central American origin (Strumigenys calamita, Strumigenys perdita, Strumigenys nastata) retain spongiform tissue on the ventral surface of the petiole and have two pairs of short erect hairs on the cephalic dorsum. In the last two species, Strumigenys epelys and silvestrii, the petiole lacks spongiform tissue ventrally and the cephalic dorsum bears only a single pair of short erect hairs. Of these two species epelys lacks the projecting hairs on the head and alitrunk that are listed above for silvestrii. Finally, silvestrii is the only species of the 6 to have its distal preapical tooth set very close to the apicodorsal tooth.

Distribution
This taxon was described from Argentina. It is also found in Brazil, Paraguay, United States, Cuba, Dominican Republic, Greater Antilles, Bahamas, Iberian Peninsula, Portugal, Hispaniola.

Nomenclature

 *  silvestrii. Strumigenys silvestrii Emery, 1906c: 168, fig. 27 (w.q.) ARGENTINA. Senior synonym of caribbea: Brown, 1959f: 25. See also: Bolton, 2000: 559.
 * caribbea. Strumigenys (Strumigenys) caribbea Weber, 1934a: 43, fig. 12 (w.q.) CUBA. Junior synonym of silvestrii: Brown, 1959f: 25.

Worker
Bolton (2000) - TL 1.6 - 2.0, HL 0.42 - 0.49, HW 0.33 - 0.37, CI 76 - 80, ML 0.22 - 0.26, MI 50 - 57, SL 0.24 - 0.31, SI 76 - 86, PW 0.21 - 0.25, AL 0.38 - 0.48 (6 measured). Apical fork of mandible usually with a minute intercalary denticle, may be very difficult to see; absent in some. Mandible with preapical tooth located very close to apicodorsal tooth; the two almost adjacent and the length of the preapical tooth greater than the distance between it and the apicodorsal. A minute denticle also present on inner margin of mandible, often difficult to see, located close to midlength. Ground-pilosity of head and leading edge of scape fine and slender, narrowly spatulate. Specialised projecting hairs on head and alitrunk stiff, feebly remiform or somewhat flattened apically: in apicoscrobal position; a short pair on cephalic dorsum close to occipital margin; at pronotal humerus; a pair on mesonotum. All hairs on first gastral tergite narrowly remiform and elevated, inclined toward midline in dorsal view, in profile appearing curved or inclined posteriorly. Petiole node in dorsal view slightly broader than long; ventral surface of petiole without spongiform tissue and lateral spongiform lobe vestigial to absent, at most nothing more than a slight expansion at apex of the posterior collar. Disc of postpetiole mostly or entirely smooth, at most with some faint superficial vestiges of sculpture.

Type Material
Bolton (2000):

Syntype workers and queen, ARGENTINA: Santa Catalina, Buenos Aires (F. Silvestri) [examined].

Strumigenys (Strumigenys) caribbea Weber, 1934a: 43, fig. 12. Syntype workers and queens, CUBA: Soledad, Cienfuegos, 15.viii.1933 (queens) (N.A. Weber); Soledad, Cienfuegos, 4.xi.1927 (workers) (W.S. Creighton) [examined].