Solenopsis clytemnestra

Workers were collected in litter samples. Solenopsis clytemnestra has been collected in wet subtropical forest between 750 - 900 m in Tucuman, Argentina. This species in Paraguay is known from shaded lawns, pasture on Fious sp. nesting in twig, grazed secondary growth on low vegetation and nesting in twig, humid subtropical medium forest on low vegetation at 500 m, humid subtropical tall forest nesting in a stick, campo cerrado edge/lagoon nesting in a stick and campo cerrado nesting in a twig. This species was collected in leaf litter in Bolivia in yungas forest, montane evergreen forest and cloud forest. (Pacheco and Mackay 2013)

Identification
A New World thief ant that is a member of the molesta species complex. (Key to New World Solenopsis Species Complexes)

Pacheco and Mackay (2013) – Worker - The workers are moderate sized, concolorous yellow (nearly always) to dark brown (rarely). The clypeal carina in most specimens is well developed. The lateral clypeal teeth are small (nearly always) angulate to well developed (rarely), while the extralateral teeth are not developed and nearly absent. The eyes are small with 5-7 ommatidia present. The petiole, as seen from above, is roughly equal in width to the postpetiole and is pyramidal with a blunt node, while the postpetiole has a rounded node. The notopropodeal suture is deeply impressed, the propodeal spiracle is very large (0.040-0.050 mm maximum diameter). Most surfaces are smooth and glossy, including the mesopleuron and much of the side of the propodeum (lower half with fine striae). What is striking about this species is the large propodeal spiracle and the small clypeal teeth. Queen -. The queen is moderately large at 4.6 mm in total length and golden brown. The space between the lateral clypeal teeth is wide at 0.102 mm and the lateral clypeal teeth are angulate. The petiolar node is thickened and wider than the petiole viewed laterally. The petiolar peduncle is lacking a tooth or flange ventrally. The propodeal spiracle is large at 0.070-0.080 mm. Male - The male is concolorous brown with pale yellow antennae. The eyes extend 0.120 mm past the lateral margin of the head and are located anteriorly on the head. The anterior lateral portion of the head between the eyes contains horizontal striae that extend between the antennal insertions. The medial ocellus is large with a diameter of 0.090 mm and a height of 0.072 mm. The propodeal spiracle is large with a diameter of 0.090 mm and has depth within the sculpture of the propodeum. The petiole is wider than the postpetiole in profile.

This is a highly variable species. Solenopsis clytemnestra can be concolorous yellow to a concolorous dark brown (specimens from Brazil, Solenopsis brasiliana and Solenopsis reichenspergeri are in our view only dark color variants). The variety leda has well developed lateral clypeal teeth compared to the nominal form; however, the degree of development of these teeth is highly variable overall populations assigned to S. clytemnestra and thus is also not recognized as a distinct taxon. Solenopsis clytemnestra strangulata is slightly darker (more reddish/ orange instead of being yellow to dark brown) and is also perceived to be a color variant because it falls within the size range of clytemnestra proper and has similar clypeal teeth. Diagnostic for this species concept of S. clytemnestra is the large propodeal spiracle, shared by all specimens of putative varieties and subspecies.

This species is also similar to Solenopsis helena and Solenopsis major whose distributions overlap that of S. clytemnestra, but can be separated from these by the large propodeal spiracle and more robust petiolar node (the latter which is completely lacking in S. helena and S. major).

Distribution
Bolivia (Santa Cruz, Cochabamba); (From Kempf, 1972) Brazil (Rio Grande do Sul), Ceara, Rio de Janeiro, Rio de Janeiro, Minas Gerais; Paraguay; Argentina (Buenos Aires, La Plata, Entre Rios, Misiones, Rio Negro, Tucuman).

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Bolivia, Brazil , Paraguay, Uruguay.

Nomenclature

 *  clytemnestra. Solenopsis clytemnestra Emery, 1896g: 87 (w.) BRAZIL. Emery, 1906c: 124 (m.). Senior synonym of brasiliana, bruchi, leda, reichenspergeri, strangulata: Pacheco & Mackay, 2013: 135.
 * brasiliana. Solenopsis brasiliana Santschi, 1925d: 235 (w.) BRAZIL. Junior synonym of clytemnestra: Pacheco & Mackay, 2013: 135.
 * bruchi. Solenopsis clytemnestra r. bruchi Forel, 1912g: 6 (w.m.) ARGENTINA. Santschi, 1933e: 115 (q.). Junior synonym of clytemnestra: Pacheco & Mackay, 2013: 135.
 * leda. Solenopsis clytemnestra var. leda Forel, 1913l: 221 (w.) BRAZIL. Junior synonym of clytemnestra: Pacheco & Mackay, 2013: 135.
 * reichenspergeri. Solenopsis reichenspergeri Santschi, 1923c: 256 (w.) BRAZIL. Borgmeier, 1929: 211 (q.). Junior synonym of clytemnestra: Pacheco & Mackay, 2013: 135.
 * strangulata. Solenopsis clytemnestra r. strangulata Forel, 1913l: 221 (w.) BRAZIL. Junior synonym of clytemnestra: Pacheco & Mackay, 2013: 135.

Worker
Pacheco and Mackay (2013) - Measurements (n=9). TL 1.56-2.01 (1.84); HL 0.480-0.540 (0.507); HW 0.378-0.480 (0.428); EL 0.048-0.066 (0.058); ED 0.030-0.042 (0.035); SL 0.300-0.396 (0.345); FSL 0.102-0.150 (0.115); CI 75.9-92.9 (84.3); SI 62.5-77.4 (67.8); PL 0.090; PW 0.114-0.150 (0.128); PI 60.0-78.9 (70.7); PPL 0.114-0.120 (0.119); PPW 0.132-0.180 (0.151); PPI 66.7-86.9 (79.6); WL 0.360; PSL 0.036-0.048 (0.041); PSW 0.030-0.048 (0.035).

Moderately large; concolorous yellow to concolorous brown; head subquadrate, longer than wide, posterior border slightly concave, finely punctate; lateral clypeal teeth angulate to well developed, extralateral teeth angulate to absent; clypeal carinae weakly to well defined (both teeth and carinae vary with specimens); scapes long, extending ~ ¾ length of head to posterior lateral corner; eyes small, black with 5-7 ommatidia; notopropodeal suture well depressed, groove breaks sculpture of mesosoma; pronotum and mesopleuron smooth and shiny; metapleuron (and occasionally katepisternum) horizontally striated; propodeal spiracle large; petiole roughly equal in width to postpetiole, pyramidal, blunt node viewed dorsally; postpetiolar node rounded.

Hairy; erect and suberect hairs present on all body surfaces; scape with numerous suberect hairs of various lengths; dorsum of head, dorsum of mesosorna, petiole and gaster have several erect hairs.

Queen
Pacheco and Mackay (2013) - Measurements (n=1). TL 4.68; HL 0.648; HW 0.588; EL 0.198; ED 0.174; MOL 0.054; MOD 0.066; SL 0.450; FSL 0.180; CI 64.1; SI 49.0; PSL 0.078; PSW 0.072; PL 0.150; PW 0.240; PI 62.5; PPL 0.150; PPW 0.270; PPI 55.6; WL 0.960.

Moderately large, concolorous golden brown; head subquadrate, longer than wide, straight posterior border, finely punctate; lateral clypeal teeth angulate, extralateral teeth absent; clypeal carinae well defined; eyes large; scape does not reach posterior border of head; medial ocellus small; pronotum and mesopleuron smooth and shiny; metapleuron horizontally striated; posterior propodeal margin rounded, propodeal spiracle large; petiole thickened, wider than postpetiole viewed laterally; petiole lacking tooth or flange ventrally.

Moderately hairy, erect and suberect hairs of various lengths covering all body surfaces; suberect hairs on petiole and postpetiole curve posteriorly.

Male
Pacheco and Mackay (2013) - Measurements (n=3). TL 3.84-3.96 (3.92); HL 0.480-0.510 (0.498); HW 0.510-0.528 (0.520); EL 0.252-0.276 (0.266); ED 0.222-0.240 (0.234); MOL 0.084-0.096 (0.090); MOD 0.096-0.102 (0.098); SL 0.210-0.228 (0.216); FSL 0.900-0.960 (0.930); CI 102-106 (104); SI 41.2-47.5 (43.4); PSL 0.090-0.102 (0.094); PSW 0.096-0.108 (0.102); PL 0.138-0.144 (0.140); PW 0.252-0.258 (0.254); PI 53.5-57.1 (55.1); PPL 0.168-0.180 (0.176); PPW 0.300; PPI 56.0-60.0 (58.7); WL 1.08.

Moderately large, concolorous brown with yellow antennae; head wider than long, striated; eyes large, located anteriorly on head, extend 0.120 mm past lateral margin of the head; medial ocellus large; propodeal spiracle large; posterior propodeal margin rounded; petiole wider than postpetiole viewed laterally, both lacking tooth or flange ventrally.

Abundantly hairy; erect and suberect hairs of various lengths on all body surfaces; hairs on petiole and postpetiole curve posteriorly.

Type Material
Pacheco and Mackay (2013) - Brazil, Rio Grande do Sul, (lectotype worker, 1 paralectotype worker [here designated], Ihering ). Solenopsis clytemnestra bruchi, Argentina, La Plata, (3 paralectotype males (Dr Bruch), Forel Coll. ). Solenopsis clytemnestra leda, Brazil, Rio de Janeiro, (lectotype worker and 5 paralectotype workers, 1 paralectotype queen, Forel coll. ). Solenopsis clytemnestra strangulata, Brazil, Minas Gerais, lectotype worker and 2 paralectotype workers, Coll. A. Forel ). Solenopsis reichenspergeri, BRAZIL, Rio de Janeiro, (lectotype worker and 3 paralectotype workers ). Solenopsis braziliana, Brazil, Bahia, (lectotype worker [here designated] Somet. M.C.Z.C. 1, 20945. Wm. M. Wheeler ).