Solenopsis gensterblumi

Nothing is known about the biology of .

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

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.


 * Key to New World Solenopsis Species Complexes

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

Castes
Queens have yet to be collected.

Nomenclature

 * . Solenopsis picta r. gensterblumi Forel, 1901d: 298 (w.) BRAZIL (Rio Grande do Sul).
 * Type-material: syntype workers (numbers not stated).
 * Type-locality: Brazil: Pelotas (Gensterblum).
 * [Note: Pacheco & Mackay, 2013: 159, mistakenly give the type-locality as Argentina: Bueos Aires, Serra de la Ventana (Bruch), and incorrectly designate a lectotype + paralectotypes from this series; the designation is redundant.]
 * Type-depository: MHNG.
 * [Misspelled as gerstenblumi by Emery, 1922e: 200, Borgmeier, 1927c: 106.]
 * Subspecies of picta: Forel, 1908c: 364; Forel, 1911c: 298; Luederwaldt, 1918: 43; Emery, 1922e: 200; Borgmeier, 1927c: 106; Ettershank, 1966: 141.
 * Subspecies of nigella: Creighton, 1930b: 132; Kempf, 1972a: 238; Bolton, 1995b: 388.
 * Status as species: Pacheco & Mackay, 2013: 158 (redescription).
 * Senior synonym of carettei: Pacheco & Mackay, 2013: 158.
 * Senior synonym of prevalens: Creighton, 1930b: 132; Kempf, 1972a: 238; Bolton, 1995b: 388; Pacheco & Mackay, 2013: 158.
 * Distribution: Argentina, Brazil.
 * carettei. Solenopsis angulata r. carettei Forel, 1913l: 223 (w.) ARGENTINA (Mendoza).
 * Type-material: lectotype worker (by designation of Pacheco & Mackay, 2013: 159), 4 paralectotype workers.
 * Type-locality: lectotype Argentina: Mendoza (C. Bruch); paralectotypes with same data.
 * Type-depository: MHNG.
 * Subspecies of angulata: Forel, 1914d: 278; Bruch, 1914: 222; Bruch, 1915: 531; Bruch, 1916: 319; Santschi, 1916b: 510; Santschi, 1916e: 378; Gallardo, 1919b: 245; Emery, 1922e: 199; Santschi, 1929d: 298; Creighton, 1930b: 149; Ettershank, 1966: 140; Kempf, 1972a: 233; Bolton, 1995b: 386.
 * Junior synonym of gensterblumi: Pacheco & Mackay, 2013: 158.
 * prevalens. Solenopsis nigella st. prevalens Santschi, 1923c: 257 (s.w.) ARGENTINA (Buenos Aires).
 * Type-material: syntype workers (number not stated).
 * Type-locality: Argentina: La Plata (C. Bruch).
 * [Note: Pacheco & Mackay, 2013: 159, record 5 “cotype” (= syntype) workers from Argentina: Alta Gracia, in MCZC, but this locality is not mentioned in the original description.]
 * Type-depository: NHMB.
 * Santschi, 1929d: 297 (m.).
 * Subspecies of nigella: Santschi, 1929d: 297.
 * Junior synonym of gensterblumi: Creighton, 1930b: 132; Kempf, 1972a: 238; Bolton, 1995b: 390; 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).

References based on Global Ant Biodiversity Informatics

 * Creighton W. S. 1930. The New World species of the genus Solenopsis (Hymenop. Formicidae). Proceedings of the American Academy of Arts and Sciences 66: 39-151.
 * Cuezzo, F. 1998. Formicidae. Chapter 42 in Morrone J.J., and S. Coscaron (dirs) Biodiversidad de artropodos argentinos: una perspectiva biotaxonomica Ediciones Sur, La Plata. Pages 452-462.
 * Forel A. 1908. Ameisen aus Sao Paulo (Brasilien), Paraguay etc. gesammelt von Prof. Herm. v. Ihering, Dr. Lutz, Dr. Fiebrig, etc. Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien 58: 340-418.
 * Forel A. 1911. Ameisen des Herrn Prof. v. Ihering aus Brasilien (Sao Paulo usw.) nebst einigen anderen aus Südamerika und Afrika (Hym.). Deutsche Entomologische Zeitschrift 1911: 285-312.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Luederwaldt H. 1918. Notas myrmecologicas. Rev. Mus. Paul. 10: 29-64.
 * 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.