Solenopsis pulleni

Solenopsis pulleni was collected in a grassy playa surrounded by a ring of mesquite.

Identification
A New World thief ant that is a member of the pygmaea species complex.

Pacheco and Mackay (2013) – Worker - This species concolorous pale yellow with an elongated and coarsely punctated head. The cuticle is translucent, making the eyes difficult to see. The lateral clypeal teeth are well developed while the extralateral teeth are bumps. It is not very pilose, with short erect and suberect hairs of relatively equal length (0.02-0.03 mm) on all body surfaces.

Solenopsis pulleni may be confused with Solenopsis tonsa (Florida and Texas) but can be distinguished by the shape of the head, which is larger, wider and more robust with S. tonsa and thin, with straight lateral edges with S. pulleni. Additionally, S. pulleni is similar to Solenopsis subterranea (USA to Colombia and Venezuela). Solenopsis pulleni can be separated based on the much longer head compared to that of S. subterranea (CI 74.1-83.3 [77.2]).

Keys

 * Key to New World Solenopsis Species Complexes
 * Key to Solenopsis pygmaea species complex / Clave a las obreras del complejo Solenopsis pygmaea

Distribution
United States: New Mexico. Known only from the type locality.

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

Castes
Known only from the worker caste.

Nomenclature

 *  pulleni. Solenopsis pulleni Pacheco, Mackay & Moreno, in Pacheco & Mackay, 2013: 280, figs. 251-252, map 60 (w.) U.S.A.

Worker
Measurements (n=4). TL 1.38-1.44 (1.43); HL 0.390-0.408 (0.396); HW 0.276-0.294 (0.284); EL 0.024; ED 0.018; SL 0.210-0.222 (0.215); FSL 0.066-0.078 (0.072); CI 127.0-136.1 (132.2); SI 52.9-56.9 (54.2); PL 0.072; PW 0.090-0.096 (0.092); PI 75.0-80.0 (78.8); PPL 0.090-0.102 (0.098); PPW 0.108; PPI 83.3-94.4 (90.3); WL 0.288-0.300 (0.294); PSL 0.018; PSW 0.018.

Concolorous pale yellow; head elongate, dorsal and ventral surfaces flat, sides of head straight, posterior border deeply concave; lateral clypeal teeth well developed, medial tooth absent, extralateral bumps weakly developed; scape extends slightly more than half length of head; eye barely visible, same color as cuticle, ommatidia not evident; mesosoma and petiole as in other members of the complex.

Short (0.020 mm), erect hairs sparse on head, antenna not very hairy, especially club, scape with few suberect hairs; all body surfaces with scattered erect and suberect hairs.

Type Material
Holotype worker [] and 15 paratype workers (,, , , , MCZC, , , ), USA, New Mexico, Dona Ana Co., Jornada Playa, 8-x-1986, B. Pullen #10.

Etymology
Named to honor Barry Pullen, who collected the type series, as well as several other interesting ants.