Solenopsis latastei

Snelling and Hunt (1975) state that S. latastei is common and widely distributed.

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 This is a golden brown species. The lateral clypeal teeth are well developed while the extralateral teeth are only present as small angles. The clypeal carinae are well developed and extend posteriorly between the antennal insertions. The pronotum has small punctures. The mesopleuron and the metapleuron below the spiracle have fine horizontal striae. The petiole is wider than the postpetiole when viewed in profile. The Subpeduncular process has a small tooth. Queen The concolorous golden brown queens are very large at 5.4 mm in length. The gaster is about half the length of the body. The head is as long as wide. The clypeal region between the lateral teeth is very concave and the lateral teeth are very long (~0.06 mm). The extralateral teeth are present as angles. The frontal lobes have vertical striae. The head and pronotum are covered with small punctures with hairs extending from each. There are thin carinae that extend horizontally on the bottom of the mesosoma and extend toward the end of the propodeum. There is a tooth present on the subpeduncular process. Male The male is concolorous dark brown. There are very small punctures present on the head (almost invisible). The clypeal margin is slightly convex with no presence of teeth, angles or bumps. The three ocelli are clear, but the eyes are black. The eyes cover about V3 of the side of the head. The body is smooth and glossy. What is striking about the male is a tooth is present on the ventral surface of the petiolar peduncle and a more developed tooth present on the bottom of the postpetiole with erect hairs extending out from it.

Solenopsis latastei may be confused with the widespread Solenopsis picea. The workers may be distinguished from those of S. picea, which are never golden brown (dark brown to black and occasionally bicolored in S. picea). Additionally, the queen of S. picea has vertical striae on the frontal lobes that extend posteriorly on the dorsum of the head (restricted to lobes on the queen of S. latastei). Moreover, these two species can be distinguished as the eye of the male of S. picea is much larger at 0.3 mm in total length (0.17-0.22 mm in S. latastei).

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Chile.

Nomenclature

 *  latastei. Solenopsis latastei Emery, 1895i: 13, figs. (w.q.) CHILE. Menozzi, 1935c: 320 (m.). Senior synonym of hoffmanni: Snelling & Hunt, 1976: 87. Current subspecies: nominal plus masora.
 * hoffmanni. Solenopsis latastei var. hoffmanni Forel, 1912g: 7 (w.q.) CHILE. Junior synonym of latastei: Snelling & Hunt, 1976: 87; Pacheco & Mackay, 2013: 202.
 * masora. Solenopsis latastei var. masora Forel, 1912g: 7 (w.) "Pemnes" (Chile ?). Junior synonym of latastei: Pacheco & Mackay, 2013: 202.
 * weiseri. Solenopsis tenuis r. weiseri Forel, 1914d: 278 (w.q.m.) ARGENTINA. Raised to species: Santschi, 1923c: 258. Junior synonym of latastei: Pacheco & Mackay, 2013: 202.

Description
Remarquable par sa coloration foncee, sa surface lisse, ses yeux rudimentaire chez l'ouvriere, associes a des antennes assez longues et minces.

Worker
Noir de poix en dessus, roux testace dans les parties inferieures du corps. Dessus de la tete, excepte le bord de l'epistome, dessus du promesonotum, metanotum, sommet des noeuds du pedicule noir de poix ; abdomen brun fonce, avec le bord des segments et une tache plus ou moins developpee au bord du segment basal testaces; scape et massue des antennes bruns, funicule testace; mandibules testacees; pattes brunes, avec les articulations, le dessous des tarses et leur extremite testaces. Du reste, la distribution des cou leurs est sujette a varier. Tout le corps est lisse et luisant avec des points fins tres epars, portant les poils dresses peu nombreux ; pubescence a peu pres nulle sur le trone, abondante sur les pattes; scapes et pattes avec quelques poils dresses.

Tete subrectangulaire, plus longue que large, faiblement echancree en arriere; yeux tres petits, de forme irreguliere; epistome arme de deux pointes aigues, en dehors desquelles l'on apercoit, tout pres d'elles, un petit angle saillant. Mandibules a 4 fortes dents pointues. Le scape atteint presque le bord occipital, dont il est separe par un intervalle moindre que son epaisseur ; les articles moyens du funicule a peu pres aussi longs que larges. Dos du corselet a suture mesometanotale fortement imprimee; metanotum a face basale assez convexe, formant avec la face declive un angle tres obtus et arrondi. Pedicule a 1er segment nettement .petiole en avant, surmonte en arriere d'un nceud arrondi; 2eme segment en ovale faiblement transversal, un peu plus large que le precedent, plus bas que lui, legerement penche en avant.

Long. 1 3/4 - 2 mm.

Pacheco and Mackay (2013) - Measurements (n=6). TL 1.68-2.18 (1.87); HL 0.402-0.582 (0.518); HW 0.390-0.528 (0.468); EL 0.036-0.060 (0.053); ED 0.030-0.036 (0.032); SL 0.318-0.408 (0.377); FSL 0.138-0.180 (0.157); CI 84.9-97.0 (90.5); SI 70.1-79.1 (73.1); PL 0.090-0.108 (0.100); PW 0.108-0.162 (0.141); PI 66.7-83.3 (71.6); PPL 0.120-0.150 (0.140); PPW 0.144-0.210 (0.176); PPI 71.4-83.3 (79.8); WL 0.360-0.480 (0.410); PSL 0.030-0.036 (0.033); PSW 0.030.

Golden brown, gaster darker brown; head longer than wide, with small punctures; lateral clypeal teeth well developed, extralateral teeth angular; clypeal carinae well developed, extending posteriorly toward antennal insertions; frontal lobes vertically striated; scape extends ¾ length of head; pronotum with small punctures; notopropodeal suture well depressed, groove breaks sculpture of mesosoma; mesopleuron and metapleuron basally below spiracle with fine horizontal striae; petiole wider than postpetiole when viewed laterally; subpeduncular process with small tooth; postpetiole rhombus-like in shape laterally.

Moderately hairy, with short erect and suberect hairs present on all body surfaces; legs pubescent; petiole, postpetiole and first tergum of gaster with suberect hairs that extend posteriorly.

Queen
Noire, mandibules, funicules, articulations des patteset tarses roux. Tete plus large que longue; angle de l'epistome en dehors des pointes plus marque que chez l'ouvriere; l'extremite du scape depasse la moitie de la distance qui separe l'ceil de l'angle paste rieur de la tete. La tete est marquee de gros points ou fossettes portant de longs poils. Corselet robuste, le metanotum forme de chaque cote un angle obtus et arrondi; ses flanes sont rugueux, tandis que le reste du corselet est lisse et luisant, pique de points piligeres. 1er segment du pedicule avec un grand noeud transversal, subsquamiforme, a bord arrondi; 2eme segment bien plus large, en ovale fortement transverse, du double plus large que long. Ailes a peine jaunatres, a points et nervures brun clair.

Long. 4 mm.

Pacheco and Mackay (2013) - Measurements (n=4). TL 4.32-6.00 (5.13); HL 0.750-0.798 (0.785); HW 0.720-0.888 (0.825); EL 0.180-0.198 (0.189); ED 0.120-0.180 (0.146); MOL 0.048-0.066 (0.060); MOD 0.054-0.060 (0.057); SL 0.510-0.558 (0.537); FSL 0.300-0.330 (0.308); CI 96.0-112.0 (105.0); SI 25.0-69.9 (57.7); PSL 0.054-0.060 (0.059); PSW 0.054-0.060 (0.059); PL 0.150-0.168 (0.158); PW 0.282-0.384 (0.347); PI 43.3-53.2 (45.9); PPL 0.264-0.324 (0.297); PPW 0.420-0.546 (0.509); PPI 54.9-62.9 (58.7); WL 0.960-1.20 (1.14).

Large; concolorous golden brown; head as long as wide; clypeal region between lateral teeth concave; lateral teeth long, extend ~0.060 mm past anterior clypeal margin; extralateral teeth small, angular; frontal lobes with vertical striae; eyes large; thin carina extends horizontally basally on mesosoma; petiole wider than postpetiole when viewed laterally, subpeduncular process with tooth; postpetiole wider than petiole viewed dorsally; fine punctures on first tergum of gaster; pigmented "fingers" present just before end of each tergum.

Head covered in small punctures with hairs extending from each; pronotum has punctures with hairs extending from each; hair covering all body surfaces; head, scape and mesosoma heavily pilose with short suberect hairs; petiole, postpetiole and gaster covered in short suberect hairs that curve posteriorly.

Male
Pacheco and Mackay (2013) - Measurements (n=3). TL 3.00-3.22 (3.13); HL 0.312-0.420 (0.372); HW 0.372-0.438 (0.398); EL 0.174-0.216 (0.192); ED 0.150-0.168 (0.156); MOL 0.042-0.060 (0.050); MOD 0.060-0.072 (0.064); SL 0.090-0.168 (0.126); FSL 0.720; CI 114.0-200.0 (145.0); SI 23.4-90.3 (50.7); PSL 0.048-0.060 (0.054); PSW 0.042-0.050 (0.048); PL 0.120; PW 0.204-0.240 (0.222); PI 50.0-58.8 (54.4); PPL 0.180-0.300 (0.240); PPW 0.216-0.252 (0.234); PPI 83.3-119.0 (101.0); WL 0.720-0.840 (0.760).

Dark brown; fine cephalic punctures (almost not visible); clypeal margin slightly convex without presence of teeth, angles or bumps; eyes large, cover 1/3 of side of head, extend nearly to anterior of head; eyes brownish yellow; sculpture of body smooth and glossy; fine pronotal punctures; petiolar peduncle and postpetiole both with ventral teeth.

Hair present (erect and suberect) on body surfaces; however, male not heavily pilose; tooth present ventrally on postpetiole with erect hairs extending out from it.

Type Information
Santa Rita, pres Santiago, 17 janvier 1895 (Santa Rita, near Santiago). Col. M. Lataste.

Etymology
In honor of the collector.

References based on Global Ant Biodiversity Informatics

 * Emery C. 1906. Studi sulle formiche della fauna neotropica. XXVI. Bullettino della Società Entomologica Italiana 37: 107-194.
 * Forel A. 1918. Quelques fourmis de Madagascar récoltées par le Dr. Friederichs et quelques remarques sur d'autres fourmis. Bulletin de la Société Vaudoise des Sciences Naturelles. 52: 151-156.
 * Goetsch W. and C. Menozzi. 1935. Die Ameisen Chiles. Konowia 14: 94-102
 * Goetsch, W., and C. Menozzi. "Die Ameisen Chiles." Konowia 14 (1935): 94-102.
 * Kempf W. W. 1970. Catálogo das formigas do Chile. Papeis Avulsos de Zoologia (São Paulo) 23: 17-43.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Pacheco J. A., and W. P. Mackay. 2013. The systematics and biology of the New World thief ants of the genus Solenopsis (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 501 pp.
 * Snelling R. R., and J. H. Hunt. 1975. The ants of Chile (Hymenoptera: Formicidae) Revista Chilena de Entomología 9: 63-129.