Solenopsis azteca

These ants are found in litter in dry forests and in nests with the termite Amitermes medius. Specimens are most commonly collected in litter samples or in pitfall traps. Specimens from the Parque Nacional H. Pittier were collected at Vienna sausage surface bait. They can be collected in primary tropical forest. (Pacheco and Mackay 2013)

Identification
Pacheco and Mackay (2013) – Worker - The workers of this species are small and color ranges from light yellow to light brown. The head is nearly quadrate and finely punctate. The clypeus is flat, with angular lateral teeth. The scape and minor funicular segments are short. The petiole is wider than the postpetiole viewed laterally. Queen - undescribed).The anterior clypeal margin of the queen is straight and the clypeus is lacking teeth. The frontal lobes are vertically striated with the striae extending posteriorly midway to the dorsum of the head. The eye is large and slightly kidney-shaped. The queen is hairy with long hairs of various lengths (0.06-0.18 mm) on all body surfaces.

Wheeler (1908a) recognized yellow specimens as the subspecies pallida. Color in this species ranges from yellow to brown, with intermediates of all colors occurring (both yellow and brown forms are found in Barbados). Pale yellow specimens occur on Puerto Rico (and exemplify the type series), as well as on Jamaica, Guatemala and Colombia.

The workers are similar to Solenopsis terricola and Solenopsis brevicornis in that all species have short antennal scapes and overlap in their distributions. Although color is often an unimportant character within the thief ants, Solenopsis azteca can be separated on the basis of color, as it is yellow to pale brown while S. terricola (from Central America) is black with yellow appendages. Moreover, S. azteca can further be separated as it lacks sculpturing on the frontal lobes as well as the mesopleuron, whereas S. terricola has vertical striation on the frontal lobes and the mesopleuron is punctated. If a queen is collected, the queen of S. terricola has roughened sculpturing on the petiole and postpetiole, whereas only the basal parts of the petiole and postpetiole are striated in S. azteca. Solenopsis azteca workers can be separated from those of S. brevicornis in that the side of petiole is sculptured, but is completely smooth and glossy in S. azteca.

Solenopsis azteca can be confused with Solenopsis zeteki in the Caribbean as they have both have moderately large eyes and reduced or absent clypeal teeth. However, S. azteca has a no clypeal teeth (resembling the minor workers of the wasmannii group), a short scape and a robust petiole viewed laterally. Solenopsis zeteki can be distinguished as it has angulate lateral clypeal teeth (although greatly reduced), a longer scape and a triangular petiolar node.

Distribution
Honduras south to Colombia (Cauca) and northern Venezuela, Caribbean Region.

Distribution based on Regional Taxon Lists
Neotropical Region: Barbados, Colombia, Dominica, Greater Antilles, Grenada, Guatemala, Jamaica, Lesser Antilles, Panama, Puerto Rico, Saint Lucia, Saint Martin (French part), Saint Vincent and the Grenadines, Venezuela.

Nomenclature

 *  azteca. Solenopsis azteca Forel, 1893g: 390 (w.) ANTILLES. Senior synonym of pallida: Pacheco & Mackay, 2013: 111.
 * pallida. Solenopsis azteca var. pallida Wheeler, W.M. 1908a: 131 (w.) PUERTO RICO. Junior synonym of azteca: Pacheco & Mackay, 2013: 111.

Worker
Pacheco and Mackay (2013) - Measurements (n=5). TL 1.32-1.36 (1.34); HL 0.390-0.408 (0.397); HW 0.324-0.342 (0.336); EL 0.042; ED 0.036; SL 0.216-0.228 (0.223); FSL 0.078-0.084 (0.082); CI 83.1-86.4 (84.6); SI 55.2-57.6 (56.2); PL 0.084-0.090 (0.086); PW 0.12; PI 70.0-75.0 (72.0); PPL 0.108-0.120 (0.110); PPW 0.120-0.144 (0.132); PPI 78.3-90.0 (83.9); WL 0.276-0.288 (0.282); PSL 0.024-0.030 (0.028); PSW 0.024-0.030 (0.026).

Small; concolorous light yellow to light brown; head nearly quadrate, cephalic punctures fine, area between punctures smooth and shiny; eye with four ommatidia; clypeus flat, lacking lateral and extralateral teeth; scape and minor segments of funiculus short; notopropodeal suture well depressed; petiole wide viewed laterally.

Hairs vary in length, including those on gaster; scape has few erect and suberect, long hairs.

Queen
Pacheco and Mackay (2013) - Measurements (n=1). TL 3.48; HL 0.582; HW 0.528; EL 0.198; ED 0.174; MOL 0.048; MOD 0.066; SL 0.324; FSL 0.156; CI 90.7; SI 55.7; PSL 0.054; PSW 0.078; PL 0.15; PW 0.24; PI 62.5; PPL 0.18; PPW 0.24; PPI 75; WL 0.72.

Bicolored, golden yellow head and mesosoma, golden brown gaster; head quadrate, longer that wide, sparsely semi-coarsely punctate; anterior clypeal margin nearly straight; lateral and extralateral teeth absent; clypeal carinae well developed, frontal lobes vertically striated, with striae extending posteriorly midway to posterior border of head; eye large (approximately 120 ommatidia), slightly kidney-shaped; medial ocellus small, lateral ocelli slightly larger; scape short; pronotum sparsely semi-coarsely punctate, posterior margin of propodeum slightly angulate; propodeal spiracle large; metapleuron horizontally striated; petiolar node with rounded triangular node, with thin, horizontal striae basally, subpeduncular process with angled tooth; postpetiole globose, horizontally striated basally, lacking tooth or flange ventrally.

Hairy, pilosity yellow, with long hairs of various lengths (0.06-0.18 mm) on all body surfaces, scape with numerous hairs (up to 0.12 mm in length).

Type Material
Antilles Islands, San Vicente, (lectotype worker and 5 paralectotypes workers [here designated] ). Solenopsis azteca pallida Wheeler, Porto [sic] Rico (Puerto Rico), Coamo Springs, (25 cotype workers, W. M. Wheeler, Type # 9248 ). Solenopsis azteca pallida, Porto [sic] Rico (Puerto Rico), Coamo Springs, (4 cotypes workers ).