Strumigenys schulzi

Dozens of samples of this species have come from wet forest sites with the majority obtained from litter samples.

Identification
Bolton (2000) - A member of the Strumigenys schulzi-group. The material examined shows variation between the series in degree of punctation of the mesopleuron, length of propodeal teeth and width of the lamella on the declivity, number of standing hairs both close to the occipital margin and on the mesonotum, size of eye, length of petiolar peduncle and degree of impression of the metanotal groove. It is presently impossible to say how many genuine species are represented here as the total amount of material available for examination is so scanty. For the present I have decided to include all the material under a single name, with the diagnosis given above, until the time that a more detailed analysis can be made.

Within the schulzi-group six species have a pronotal humeral hair present: Strumigenys castanea, Strumigenys metrix, Strumigenys orchibia, schulzi, Strumigenys urrhobia and Strumigenys emiliae. Of these urrhobia and emiliae have very derived and specialised dentition, relatively small eyes with 10 or fewer ommatidia in total, slender scapes that are over 4.5 X longer than broad and a postpetiole disc that is not entirely blanketed with reticulate-punctate sculpture. By comparison the other four together have more generalised dentition (see above), much larger eyes with at least 20 ommatidia in total, broad flattened scapes that are less than 4.0 X longer than broad and a postpetiole disc that is entirely coarsely reticulate-punctate.

Of the four species metrix is much darker in colour than schulzi, being dark brown with a blackish-brown gaster, and its mesonotal standing hairs are very short and stubbly, indistinct and not much longer than the ground-pilosity. S. schulzi on the other hand is uniformly yellow to brownish yellow and its mesonotal standing hairs are longer and very distinctly differentiated from the sparse ground-pilosity. S. orchibia is a larger species than schulzi, with only a single pair of mesonotal erect hairs and much longer, finer and denser basigastral costulae. The separation of castanea from schulzi rests, rather uneasily, on the character given in the key. The two are extremely close and may be synonymous, but more material is needed for analysis before a definite statement can be made.

Longino (Ants of Costa Rica) - Mandibles in side view straight, not broadly curved ventrally; mandibles relatively short, subtriangular, much of the apical portion meeting along a serially toothed masticatory margin when closed (former Smithistruma); face punctate; leading edge of scape with a row of conspicuous projecting curved hairs, of which those distal to the subbasal bend distinctly curve toward the base of the scape; sides of posterior half of mesosoma completely and densely punctulate; ventral petiolar spongiform appendages entirely obsolete; disc of postpetiole reticulate-punctate; gaster with more than 10 erect, somewhat spoon-shaped setae; propodeal teeth broad at base and continuous with infradental lamellae; cephalic vertex with transverse row of 4 - 6 suberect hairs just behind the highest point, these hairs distinctly differentiated from the ground-pilosity; each pronotal humerus with single stout projecting hair.

Distribution based on Regional Taxon Lists
Neotropical Region: Barbados, Belize, Brazil, Costa Rica, Ecuador, Honduras, Mexico, Panama, Peru, Trinidad and Tobago, Venezuela.

Biology
Longino (Ants of Costa Rica) - The types from Brazil were from under tree bark (Brown 1953). Material from Finca Monte Libano, Ocosingo Valley, Chiapas, Mexico was found by sweeping vegetation. A dealate queen from Pueblo Nuevo, near Tetzonapa, Veracruz, Mexico was in rain forest, under bark of large (2m diameter) rotten log with wood still hard (Brown 1964). A worker I collected in Braulio Carrillo National Park was a nocturnal forager on the ground. The species has not occurred in numerous samples of sifted litter that I and others have taken from forest floor habitats. These observations suggest that this species nests and forages in the low arboreal zone, just above the soil/litter layer.

Nomenclature

 *  schulzi. Strumigenys schulzi Emery, 1894c: 213, pl. 1, fig. 7 (w.) BRAZIL. Wheeler, G.C. & Wheeler, J. 1955a: 144 (l.). Combination in S. (Cephaloxys): Emery, 1924d: 325; in Smithistruma: Brown, 1953g: 108; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 127. Senior synonym of studiosi: Bolton, 2000: 225.
 * studiosi. Strumigenys (Cephaloxys) studiosi Weber, 1934a: 44, fig. 5 (w.) COSTA RICA. Wheeler, G.C. & Wheeler, J. 1955a: 144 (l.). Combination in Smithistruma: Brown, 1953g: 104; in Pyramica: Bolton, 1999: 1673. Junior synonym of schulzi: Bolton, 2000: 225.

Worker
Bolton (2000) - TL 1.8-1.9, HL 0.50-0.55, HW 0.37-0.42, CI 74-77, ML 0.07-0.10, MI 14-18, SL 0.21-0.25, SI 56-59, PW 0.26-0.27, AL 0.50-0.56 (7 measured).

Anterior clypeal margin approximately transverse, in various specimens may appear extremely feebly convex or extremely feebly concave. Eye large, with 5-6 ommatidia in the longest row and with 20 or more ommatidia in total. Dentition as discussed in introduction to group. Scape strongly dorsoventrally compressed and wide, in dorsal view only 3.2-3.6 X longer than broad; broadest point of scape distinctly proximal of its midlength. Apicoscrobal hair short and stout, anteriorly curved; a similar hair may occur on the margin at level of eye. In profile dorsum of head between highest point of vertex and occipital margin with a transverse row of 4 - 6 anteriorly curved short hairs that are distinctly longer and more erect than the spatulate ground-pilosity. Pronotal humeral hair stout, truncated to weakly clavate apically. Mesonotal dorsum with 2-3 pairs of short stout standing hairs; similar hairs are also present on waist segments and first gastral tergite. Dorsum and side of alitrunk entirely reticulate-punctate or with a more weakly sculptured to smooth area on the katepistemum. Petiole and postpetiole reticulate-punctate dorsally, the former broader than long in dorsal view and without trace of a ventral spongiform strip. Basigastral costulae sharply defined and extending over the basal one-fifth to one-quarter of the tergite, spaces between costulae usually finely shagreenate to minutely striolate.

Type Material
Bolton (2000) - Syntype workers, BRAZIL: Para, 23/3 .93, No. 166 (A. Schulz) [examined].