Solenopsis sulfurea

Solenopsis sulfurea was collected in a humid subtropical tall forest in leaf litter in Paraguay.

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 worker can be concolorous yellow to pale yellow or bicolored with a yellow body and brown gaster. The lateral clypeal teeth are present and well developed, while the extralateral teeth are absent, but small angles are present in their position interrupting the outline of the clypeal margin. The scape is relatively long at 0.300 mm. The petiole has a small node that is triangular in shape with a minute tooth ventrally on peduncle. Queen - The queen is golden brown in color and slender in overall appearance. The head is elongate with all four well-developed clypeal teeth, while the clypeal carinae are weakly defined. The petiole and postpetiole are covered in roughened/punctate sculpturing. The petiolar peduncle has a well-developed tooth ventrally that is translucent apically. Male - The male is medium brown in color. The head is smooth and shiny with the anterior clypeal margin slightly convex, lacking teeth or bumps. The petiole and postpetiole are covered with striae. The postpetiolar node is nearly twice as high as the petiolar node.

The workers of S. sulfurea are similar to Solenopsis subtilis (Venezuela south Paraguay) and the Galapagos species, Solenopsis gnoma. Solenopsis sulfurea can be distinguished from S. subtilis as it has an elongated clypeus, while the clypeus of S. subtilis is compact. If a queen is collected, the petiole and postpetiole of S. subtilis are horizontally striated; roughened with S. sulfurea. Solenopsis gnoma also has an elongated clypeus, but has well defined clypeal carinae; weakly defined with S. sulfurea. Moreover, if a queen is collected, the head is not conspicuously elongate and the clypeal margin only has two well defined teeth with S. gnoma.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil , French Guiana, Guyana, Paraguay, Suriname, Venezuela.

Nomenclature

 *  sulfurea. Diplorhoptrum sulfureum Roger, 1862c: 296 (w.) SOUTH AMERICA. Combination in Solenopsis: Mayr, 1863: 407. Senior synonym of albidula, flava, postbrunnea: Pacheco & Mackay, 2013: 316.
 * albidula. Solenopsis albidula Emery, 1906c: 129, fig. 12 (w.q.m.) ARGENTINA. Junior synonym of sulfurea: Pacheco & Mackay, 2013: 316.
 * flava. Solenopsis albidula var. flava Santschi, 1929d: 298 (w.q.) ARGENTINA. Junior synonym of sulfurea: Pacheco & Mackay, 2013: 316.
 * postbrunnea. Solenopsis albidula var. postbrunnea Forel, 1913l: 220 (w.) BRAZIL. Junior synonym of sulfurea: Pacheco & Mackay, 2013: 316.

Worker
Pacheco and Mackay (2013) - Measurements (n=10). TL 1.22-1.46 (1.34); HL 0.372-0.468 (0.416); HW 0.288-0.408 (0.335); EL 0.030-0.054 (0.038); ED 0.030-0.036 (0.031); SL 0.246-0.300 (0.280); FSL 0.090-0.120 (0.108); CI 73.8-87.2 (80.6); SI 57.7-72.5 (67.4); PL 0.084-0.090 (0.088); PW 0.084-0.120 (0.095); PI 75.0-100 (93.8); PPL 0.090-0.096 (0.092); PPW 0.096-0.126 (0.109); PPI 71.4-100.0 (84.2); WL 0.300; PSL 0.018; PSW 0.024.

Small; concolorous yellow to bicolored with brown gaster; head much longer than wide, finely punctate; lateral clypeal teeth well developed, extralateral teeth slightly angulate; clypeal carinae poorly defined; eyes small, three ommatidia; scape long, reaching ¾ distance to posterior-lateral border of head; pronotum and mesopleuron smooth and shiny; posterior propodeal margin rounded (viewed laterally); propodeal spiracle small, round; metapleuron horizontally striated; petiole wider than postpetiole (viewed laterally); petiolar node small, triangular, peduncle with minute tooth ventrally; postpetiolar node rounded, semicircular, lacking tooth or flange ventrally.

Moderately hairy, pilosity yellow; erect and suberect hairs scattered on body surfaces; hairs on mesosoma 0.060 mm in total length; hairs on petiole and postpetiole curve posteriorly.

Queen
Pacheco and Mackay (2013) - Measurements (n=3). TL 4.08-4.20 (4.14); HL 0.630; HW 0.480-0.492 (0.484); EL 0.180-0.198 (0.188); ED 0.150-0.162 (0.159); MOL 0.042-0.048 (0.044); MOD 0.048-0.054 (0.050); SL 0.378-0.390 (0.386); FSL 0.210-0.216 (0.212); CI 76.2-78.1 (76.8); SI 60.0-61.9 (61.3); PSL 0.036-0.042 (0.041); PSW 0.036-0.042 (0.038); PL 0.150-0.156 (0.152); PW 0.210; PI 71.4-74.3 (72.4); PPL 0.240; PPW 0.258; PPI 93.0; WL 0.720-0.750 (0.728).

Moderately large; concolorous golden brown; head elongate, much longer than wide, surface finely punctate; lateral clypeal teeth well developed, space between tips of teeth wide (0.090 mm), extralateral teeth well developed; clypeal carinae weakly defined; scape yellow, long, not reaching posterior border of head; medial ocellus small; eyes large; mesosoma slender; pronotum and dorsopropodeum in same plane, with dorsal margin straight line viewed laterally; pronotum and mesopleuron smooth and shiny; posterior propodeal margin rounded (viewed laterally); metapleuron with scattered striae above and below spiracle; petiole wider than postpetiole (viewed laterally); petiolar node robust, round, triangular, peduncle with well-developed tooth ventrally, translucent apically; sides of petiole and postpetiole with striated sculpturing.

Moderately dense, pilosity yellow; erect and suberect hairs scattered on body surfaces; hairs on petiole and postpetiole long (0.012-0.015 mm), curve posteriorly.

Male
Pacheco and Mackay (2013) - Measurements (n=4). TL 3.00-3.36 (3.12); HL 0.420; HW 0.432-0.438 (0.434); EL 0.180-0.198 (0.188); ED 0.162-0.174 (0.167); MOL 0.054-0.060 (0.057); MOD 0.060; SL 0.180; FSL 0.600-0.660 (0.615); CI 102-104 (103); SI 42.9; PSL 0.042-0.048 (0.045); PSW 0.036-0.042 (0.039); PL 0.102; PW 0.180-0.210 (0.195); PI 48.6-56.7 (52.6); PPL 0.162-0.180 (0.173); PPW 0.240-0.258 (0.246); PPI 67.5-75.0 (70.1); WL 0.720.

Moderately large; concolorous medium brown; head wider than long, smooth and shiny; anterior clypeal margin convex, lacking teeth or bumps; eyes black, large; medial ocellus black, small; mesosoma smooth and shiny; posterior propodeal margin rounded (viewed laterally); propodeal spiracle small; petiolar node arched with small bump ventrally; postpetiole semicircular, twice as high as petiolar node; sides of both petiole and postpetiole with thin, broken striae.

Moderately dense, pilosity yellow; erect and suberect hairs scattered on body surfaces; most hairs long (0.120 mm).

Type Material
Diplorhoptrum sulfurea not found. Solenopsis albidula Syntypus 1906, Museo Genova coll. C. Emery (dono 1925), Argentina, Buenos Aires, Nunez, ll-xi-98 (lectotype worker, 2 paralectotype workers, 3 paralectotype queens and 3 paralectotype males [here designated] ). Solenopsis albidula postbrunnea Forel coll. Brazil, Sao Paulo (lectotype worker and 2 paralectotype workers [here designated] ). Solenopsis albidula flava Sammlung Dr. F. Santschi Kairouan Argentina, Buenos Aires, La Plata (C. Bruch) (lectotype worker, 6 paralectotype workers and 1 paralectotype queen (broken) [here designated] ). Solenopsis albidula flava cotype 1-2 20910, M.Z.C. (lectotype worker and 1 paralectotype worker ).