Solenopsis gensterblumi

Identification
Pacheco and Mackay (2013) – Worker - The worker ranges in color from concolorous golden yellow to brown. What is striking about this species are the large eyes (20-25 ommatidia). It is nearly devoid of pilosity and sculpturing and is smooth and shiny on all body surfaces. The petiolar peduncle has a well-developed ventral tooth.

Apparently S. gensterblumi is a minor worker and Solenopsis nigella is the major of the same species-level taxon. It appears that S. nigella is dimorphic, but with the little evidence (no complete series), we will recognize S. gensterblumi as a valid species. However, if and when a complete series is collected, S. gensterblumi will probably be synonymized with S. nigella.

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

Castes
Queens have yet to be collected.

Nomenclature

 *  gensterblumi. Solenopsis picta r. gensterblumi Forel, 1901d: 298 (w.) BRAZIL. [Misspelled as gerstenblumi by Emery, 1922e: 200.] Senior synonym of prevalens: Creighton, 1930b: 132; of carettei: Pacheco & Mackay, 2013: 158.
 * carettei. Solenopsis angulata r. carettei Forel, 1913l: 223 (w.) ARGENTINA. Junior synonym of gensterblumi: Pacheco & Mackay, 2013: 158.
 * prevalens. Solenopsis nigella st. prevalens Santschi, 1923c: 257 (s.w.) ARGENTINA. Santschi, 1929d: 297 (m.). Junior synonym of gensterblumi: Creighton, 1930b: 132; Pacheco & Mackay, 2013: 158.

Worker
Pacheco and Mackay (2013) - Measurements (n=14). TL 1.37-1.62 (1.53); HL 0.408-0.528 (0.483); HW 0.300-0.468 (0.410); EL 0.042-0.090 (0.079); ED 0.030-0.060 (0.053); SL 0.282-0.360 (0.308); FSL 0.090-0.144 (0.126); CI 71.4-92.6 (85.0); SI 58.1-72.3 (64.0); PL 0.066-0.078 (0.073); PW 0.078-0.102 (0.091); PI 70.6-92.3 (80.2); PPL 0.090-0.120 (0.102); PPW 0.120-0.138 (0.128); PPI 68.2-95.2 (79.6); WL 0.300-0.360 (0.309); PSL 0.024; PSW 0.018-0.024 (0.020).

Small, concolorous golden yellow to dark brown; head quadrate, longer than wide, with posterior border slightly concave; lateral clypeal teeth angulate; extralateral teeth absent; clypeal carinae well defined; scape does not reach posterior border of head; eyes large, oval shaped, approximately 20-25 ommatidia; pronotum and mesopleuron smooth and shiny; notopropodeal suture weakly depressed, groove breaks sculpture of mesosoma; metapleuron horizontally striated; posterior propodeal edge angulate, with ridge; petiolar node wider than postpetiole viewed laterally, petiole triangular shaped with sharp anterior and posterior faces; well defined tooth present ventrally on subpeduncular process.

Not very pilose; few hairs present on all body surfaces; neither head nor scape heavily pilose, with only small suberect hairs present that are roughly 0.018 mm in length; mesosoma, petiole, postpetiole and gaster have very few hairs that range from 0.018 to 0.024 mm in length.

Type Material
Pacheco and Mackay (2013) - Argentina, Buenos Aires, Serra de la Ventana, Sierra Ventana, (460, Bruch) Forel Coll. (lectotype worker [here designated] and 4 paralectotype workers ). Solenopsis nigella prevalens, Argentina, Alta Gracia, (Bruch) M.C.Z.C. 1-5, 20931 (5 worker cotypes ). Solenopsis angulata carettei, (1 lectotype worker [here designated] and 4 paralectotype workers MHNG).

Additional References

 * [[Media:Pacheco, J.A. & Mackay, W.P. 2013. The systematics and biology of the New World thief ants of the genus Solenopsis.pdf|Pacheco, J.A. & Mackay, W.P. 2013. The systematics and biology of the New World thief ants of the genus Solenopsis (Hymenoptera: Formicidae). Edwin Mellen Press, Lewiston, New York. 501 pp.]]