A revision of the fire ants, Solenopsis geminata group (Hymenoptera: Formicidae: Myrmicinae)

• Published in: Journal of the New York Entomological Society Vol. 99; no. 2; pp. 141 - 198
• Main Author: Trager, J.C. (Shaw Arboretum of the Missouri Botanical Garden, Gray Summit, MO)
• Format: Journal Article
• Language: English
• Published: Allen Press 01-04-1991
• Subjects: AMERICA DEL SUR; AMERIQUE DU SUD; Ants; Biological taxonomies; Entomology; ESPECE NOUVELLE; ESPECIES NUEVAS; Fire ants; Formicidae; Head; Hymenoptera; Insect colonies; KEYS; MORPHOLOGY; NEW SPECIES; Peduncle; Petioles; Queen insects; Solenopsis; SOLENOPSIS GEMINATA; SOUTH AMERICA; SYNONYMY; Syntypes; TAXONOMIA; TAXONOMIE; TAXONOMY; New World
• ISSN: 0028-7199; 1937-2361

The subgenera and satellite genera of Solenopsis are reviewed. Synonymy under Solenopsis of all subgenera and of the genera Bisolenopsis, Synsolenopsis, Paranamyrma, and Labauchena is confirmed. Certain placement of the genus Lilidris, known from a single alate female, will require study of additional material, but Lilidris appears to be distinct from Solenopsis. The fire ants and their close relatives, S. substituta and S. tridens, are collectively designated as the S. geminata species group, which together with the parasitic S. daguerrei group (Labauchena) form a monophyletic lineage. S. virulens, a species phenetically similar to minors of S. saevissima, is also included in this revision, though it probably does not belong in the S. geminata group. Four native species, 2 introduced species, and 2 hybrid forms occur in North America. Seventeen species are known from South America. A key to major workers and illustrations of all species are included. Notes on the identification of queens are provided where these are sufficiently distinctive. The native North American species are S. aurea Wheeler, S. amblychila Wheeler new status, S. geminata (Fabricius), and S. xyloni (MacCook), and the introduced species are S. invicta Buren and S. richteri Forel from South America. S. xyloni × geminata and S. invicta × richteri are the hybrid forms. S. invicta × richteri is abundant and highly fertile in parts of Alabama, Mississippi and northwestern Georgia in North America, but this hybrid has not been observed in South America, even though the parent species have overlapping distributions in at least Santa Fé Province, Argentina. In South America, only S. bruesi Creighton new status, S. gayi (Spinola), S. geminata and S. weyrauchi new species occur in or to the west of the Andes. The latter is unusual in that it occurs at elevations up to 3,500 m or higher in the Peruvian Andes. To the east of the Andes are found S. electra Forel new status, S. geminata, S. interrupta Santschi, S. invicta, S. macdonaghi Santschi new status, S. megergates new species, S. pusillignis new species, S. pythia Santschi, S. quinquecuspis Forel, S. richteri, S. saevissima F. Smith, S. substituta Santschi new status, and S. tridens Forel. With the exception of S. geminata, S. saevissima, and S. invicta (at least part of whose geographic range is in the rain forest region) most of the South American species are endemic to the monsoon tropics or warm temperate regions of the southern part of the continent. S. virulens (F. Smith) new status, probably not a member of the S. geminata group but superficially resembling them, inhabits the forests of Amazonia.