Solenopsis hayemi

Solenopsis hayemi nests underground and was collected on the Pacific Coast in Costa Rica. This species was collected by surface and vegetation traps baited with Vienna sausage in a primary growth area in Mexico and at tuna bait in Colombia. Solenopsis hayemi was also collected at 150 m by a malaise trap and at 900 m in the El Vintulo Forest in Colombia. This species was collected in humid subtropical medium forest foraging on low vegetation in Paraguay. (Pacheco and Mackay 2013)

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

Pacheco and Mackay (2013) - Worker - The worker of this relatively large species varies in coloration, from concolorous yellow to bicolored red and black. The sides of the head are convex with the posterior border nearly straight. The clypeal lateral teeth are poorly developed. It is easily recognized by the widely arched petiole (viewed laterally).

The worker of S. hayemi is very similar to the widely distributed Solenopsis stricta; the main difference between these two species is the form and size of the petiole viewed from above. The petiole of S. hayemi is consistently wider than that of S. stricta viewed from above. Solenopsis hayemi (Central and South America) can be confused with Solenopsis decipiens (South America) as well, but this latter species has more developed lateral clypeal teeth, with straighter lateral edges of the head and a narrower petiole compared to those features on S. hayemi.

Keys

 * Key to New World Solenopsis Species Complexes
 * Key to workers of the stricta species complex / Clave para las obreras del complejo stricta

Distribution
Mexico (Chiapas and Veracruz) south to Brazil (Sao Paulo) and Paraguay (Canindeyu).

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil, Colombia, Costa Rica , Mexico, Panama, Paraguay.

Castes
Known only from the worker caste.

Nomenclature

 * . Solenopsis hayemi Forel, 1908b: 45 (w.) COSTA RICA.
 * Type-material: lectotype worker (by designation of Pacheco & Mackay, 2013: 178).
 * [Note: other original syntypes probably present in MHNG.]
 * Type-locality: Costa Rica: El Hiquito, nr San Mateo, in houses (P. Biolley).
 * Type-depository: MCZC (lectotype).
 * Status as species: Emery, 1922e: 200; Ettershank, 1966: 141; Kempf, 1972a: 237; Bolton, 1995b: 388; Pacheco & Mackay, 2013: 177 (redescription); Fernández & Serna, 2019: 816.
 * Senior synonym of idae: Pacheco & Mackay, 2013: 177.
 * Distribution: Brazil, Colombia, Costa Rica, Mexico, Panama, Paraguay.
 * idae. Solenopsis franki subsp. idae Forel, 1908c: 365 (w.) BRAZIL (São Paulo).
 * Type-material: lectotype worker (by designation of Pacheco & Mackay, 2013: 178), 5 paralectotype workers.
 * Type-locality: lectotype Brazil: São Paulo (von Ihering); paralectotypes with same data.
 * Type-depository: MHNG.
 * Subspecies of franki: Luederwaldt, 1918: 42; Emery, 1922e: 199; Borgmeier, 1927c: 104; Ettershank, 1966: 141; Kempf, 1972a: 235; Bolton, 1995b: 388.
 * Junior synonym of hayemi: Pacheco & Mackay, 2013: 177.

Worker
Pacheco and Mackay (2013) - Measurements (n=16). TL 1.74-2.28 (1.96); HL 0.480-0.570 (0.525); HW 0.390-0.522 (0.442); EL 0.048-0.066 (0.052); ED 0.033-0.048 (0.038); SL 0.330-0.420 (0.370); FSL 0.150-0.180 (0.164); CI 75.0-91.6 (84.1); SI 67.4-73.7 (70.5); PL 0.090-0.150 (0.120); PW 0.102-0.192 (0.119); PI 68.8-132.0 (103.0); PPL 0.090-0.132 (0.122); PPW 0.126-0.198 (0.146); PPI 60.6-95.7 (83.7); WL 0.360-0.480 (0.405); PSL 0.036-0.048 (0.041); PSW 0.030-0.042 (0.033).

Relatively large; bicolored, dark reddish-brown and black species (head and mesosoma red, gaster black) to concolorous yellow; eyes moderate sized with 3-4 ommatidia; lateral clypeal teeth poorly developed, extralateral teeth absent; sides of head convex and rounded, posterior border nearly straight; scape reaches approximately 3/4 distance to posterior lateral corner of head; notopropodeal suture well depressed; petiole wide laterally, petiole and postpetiole about same height, petiole thickened yet less wide than postpetiole as viewed dorsally.

Hair fine, dispersed all over body surfaces, including gaster; second segment of club with few or no hairs; few erect long (up to 0.150 mm) hairs on mesosoma.

Type Material
Costa Rica, El Hiquito, S. Matto, Broffey (lectotype worker [here designated] #22615 ). Solenopsis franki idae, Brazil, Sao Paulo, Type (v. Ihering), #5578 (lectotype worker [here designated] and 5 paralectotype workers ).

References based on Global Ant Biodiversity Informatics

 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * 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. 1908. Fourmis de Costa-Rica récoltées par M. Paul Biolley. Bulletin de la Société Vaudoise des Sciences Naturelles 44: 35-72.
 * 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.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133