Solenopsis salina

Solenopsis salina nests under large stones in creosote desert scrub, grassland, grassland-juniper transition, hardwood oak and pine forests, in dark brown sandy soils and rocky loam soils. Several nests were found in the soil in a bare, burned area. Occasionally there is a small mound around the entrance. Two nests were under logs. One nest was found in the nest of Formica oreas, another in a nest of Pheidole porcula. Solenopsis salina appears to inhabit mesic sites frequently in New Mexico and reproductives can be found in nests in July and August (Mackay and Mackay, 2001). Workers were collected in surface, vegetation and subterranean Vienna sausage, live meal worm and fire ant baits, and in seed baits. Specimens were also collected in pitfall traps. (Mackay and Mackay 2002, 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 small, typically yellow (occasionally pale brown), in which the total length of the minor funicular segments is usually less than 0.120 mm in total length. The lateral clypeal teeth are usually bent inward and usually blunt tipped. The extralateral teeth are angulate. The hairs on the posterior tibiae are usually appressed or at most suberect. The cephalic punctures are coarse. Queen - undescribed). The queen is medium brown with a dark brown head. The head is coarsely punctate and resembles members of the fugax species complex. The space between the lateral clypeal teeth is wide at 0.120 mm. The metapleuron, petiole and postpetiole are striated. The petiolar peduncle has a flange ventrally.

The blunt, inwardly curved clypeal teeth of the worker (although a variable character in a series) will often separate this species from the similar Solenopsis texana with has straight lateral teeth and Solenopsis quadridentata which has straight, sharp lateral clypeal teeth. The cephalic punctures are moderately coarse, which also separates this species from S. texana, where the cephalic punctures are fine. The appressed or suberect hairs on the posterior tibiae will separate it from Solenopsis carolinensis (which rarely has erect hairs on the tibia). Larger workers (rare) are similar to S. molesta, but the combination of the bent clypeal teeth and the larger cephalic punctures distinguish S. salina from S. molesta. It can be also separated from S. molesta as the minor funicular segments of S. molesta are typically over 0.12 mm in length, while S. salina are typically shorter than 0.10 mm in total length.

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Mexico.

Castes
Males have yet to be collected.

Nomenclature

 *  salina. Solenopsis salina Wheeler, W.M. 1908e: 427, pl. 26, figs. 24, 25 (w.) U.S.A.

Worker
Pacheco and Mackay (2013) - Measurements (n=5). TL 1.41-1.50 (l.45); HL 0.408-0.432 (0.420); HW 0.342-0.360 (0.356); EL 0.036-0.042 (0.037); ED 0.030; SL 0.270-0.288 (0.279); FSL 0.108-0.132 (0.121); CI 83.3-85.7 (84.9); SI 63.9-68.6 (66.6); PL 0.078; PW 0.102-0.114 (0.108); PI 68.4-76.5 (72.3); PPL 0.096-0.102 (0.098); PPW 0.120-0.150 (0.133); PPI 68.0-80.0 (74.3); WL 0.300-0.330 (0.312); PSL 0.024-0.036 (0.031); PSW 0.024-0.030 (0.029).

Small, concolorous yellow to pale brown; head longer than wide, punctures on head moderately large, much larger than hairs that arise from them; lateral clypeal teeth angulate, thick, blunt at tips, often bent inward, extralateral teeth absent, angles present in their position; clypeal carinae well defined; eyes small, 3-5 ommatidia; scape does not reach posterior border of head; minor funicular segments 3-8 relatively short; pronotum and mesopleuron smooth and shiny; metapleuron with thin, faint striae; posterior propodeal margin rounded; petiole wider than postpetiole (viewed laterally); petiolar node rounded, peduncle with small tooth ventrally; postpetiolar node oval, lacking tooth or flange ventrally.

Abundantly hairy; hairs on pronotum numerous and various lengths, longest 0.012 mm in length; hairs on posterior tibiae usually appressed or suberect; hairs on petiole, postpetiole and gaster curve posteriorly.

Queen
Pacheco and Mackay (2013) - Measurements (n=2). TL 4.92-5.16 (5.04); HL 0.762-0.774 (0.768); HW 0.720; EL 0.240; ED 0.210; MOL 0.060-0.066 (0.063); MOD 0.072; SL 0.540-0.570 (0.555); FSL 0.288-0.324 (0.306); CI 93.0-94.5 (93.8); SI 70.9-73.6 (72.3); PSL 0.066-0.084 (0.075); PSW 0.054-0.060 (0.057); PL 0.192-0.210 (0.201); PW 0.360-0.378 (0.369); PI 53.3-55.6 (54.4); PPL 0.276; PPW 0.402; PPI 68.7; WL 1.20.

Moderately large; medium brown with darker head; head longer than wide, coarsely punctate; lateral clypeal teeth well developed, space between tips of teeth wide at 0.120 mm; extralateral teeth absent; clypeal carinae weakly defined; scape long, but not reaching posterior lateral corner of head; minor funicular segments 3-8 long; pronotum coarsely punctate, smooth and shiny between punctures; mesopleuron smooth and shiny; mesopleuron horizontally striated; petiole and postpetiole robust, petiolar peduncle with well-developed flange ventrally.

Abundantly hairy, yellow pilosity, sub erect to erect hairs of various lengths on all body surfaces; mesosoma very pilose, longest hairs 0.240 mm in length; hairs on petiole, postpetiole and gaster curve posteriorly.

Type Material
We were unable to locate any types of S. salina; they were apparently borrowed by Thompson in 1989 and not yet returned (S. Cover, Harvard University, MCZ, pers. comm.).