Solenopsis dysderces

This species was collected while excavating a colony of Araucomyrmex from a small cell approximately 15 cm below the ground (Snelling, 1975).

Identification
A New World thief ant that is a member of the pygmaea species complex.

Pacheco and Mackay (2013) – Worker - The worker is concolorous pale yellow. The head is elongate, sparsely punctate, yet thickened when viewed laterally from the dorsum to the ventral surface. The clypeal carinae are weakly defined. The eye consists of one ommatidium without pigment.

Solenopsis dysderces is similar to Solenopsis leptanilloides (Argentina) as both species have noticeably elongate heads, similar forms of the clypeus and a lack of well-defined clypeal carinae. Close comparison reveals that S. dysderces has a larger head, in length, width and when measured from the dorsal to ventral surface. Solenopsis leptanilloides has a noticeably slender body compared to the more robust S. dysderces. Solenopsis dysderces is only known from the mountains of Chile, while S. leptanilloides is found in Northeastern Argentina. Solenopsis dysderces is also similar to Solenopsis minutissima (from northeastern Argentina). Solenopsis minutissima can be separated as it has a quadrate shaped head, coarse cephalic punctures and a shorter scape.

Distribution
Known only from the type locality: Aconcagua, Chile.

Distribution based on Regional Taxon Lists
Neotropical Region: Chile.

Castes
Known only from the worker caste.

Nomenclature

 *  dysderces. Solenopsis dysderces Snelling, R.R. 1975: 2, figs. 1, 2 (w.) CHILE.

Worker
Pacheco and Mackay (2013) - Measurements (n=3). TL 1.26-1.32 (1.28); HL 0.420-0.426 (0.422); HW 0.312; EL 0.024; ED 0.018; SL 0.300-0.306 (0.302); FSL 0.108-0.114 (0.110); CI 73.2-74.3 (73.9); SI 70.4-72.9 (71.6); PL 0.072-0.078 (0.076); PW 0.096; PI 75.0-81.3 (79.2); PPL 0.096-0.102 (0.100); PPW 0.102; PPI 94.1-100 (98.0); WL 0.270-0.288 (0.282); PSL 0.018; PSW 0.024-0.030 (0.028).

Small; concolorous pale yellow; head elongated, longer than wide, finely punctate, punctures sparse, posterior border slightly concave; anterior clypeal margin between lateral teeth concave; lateral clypeal teeth well developed; bumps present at extralateral position; clypeal carinae weakly defined; scape relatively long, minor funicular segments relatively long; eye with one ommatidium, lacking pigment; pronotum finely punctate, punctures sparse; mesopleuron smooth and shiny, lacking sculpturing; propodeal posterior margin rounded; mesopleuron horizontally striated; petiole node rounded, wider than postpetiole viewed laterally, lacking tooth or flange ventrally, but with little bump; postpetiolar node circular viewed dorsally, lacking tooth or flange ventrally.

Moderately hairy, pilosity pale yellow; scape with appressed and suberect hairs; head, mesosoma, petiole, postpetiole and gaster with short (0.030-0.066 mm) suberect hairs of various lengths.

Type Material
Pacheco and Mackay (2013) - Chile, Aconcagua, ca. 3 km N of Zapallar, 28-x-1972, J. H. Hunt # 958 (holotype and 5 paratype workers,, 3 paratypes seen).