Pheidole radoszkowskii

P. radoszkowskii prefers relatively open, dry habitats and does especially well in places modified by human activity. I collected it from along a hotel seawall on Tobago. On St. Vincent, H. H. Smith (cited by Forel 1893j, who described the accessions as “variety luteola”) found it common in open environments from sea level to the edge of the Soufrière Volcano at about 900 meters. Nests on St. Vincent, Smith noted, are usually in the soil beneath a stone or piece of wood in open ground, less commonly within pieces of rotting wood or in rubbish. When beneath an object, the nest is composed of a vertical chamber 8–12 mm wide that branches downward a half dozen cm or so and ends in small chambers 2–3 cm wide. Colonies grow to contain two or three thousand workers, about one-fifth of which are majors. There is apparently only a single fertile queen. In Costa Rica, Longino (1997) found “variety luteola” in similar habitats to those reported by Smith on St. Vincent, nesting beneath dead wood on the ground. Workers forage during the day over the ground and on low vegetation. On Tobago I found they could be recruited in large numbers with baits. Studying the species in Costa Rica, Roberts and Heithaus (1986) observed workers collecting seeds and thus helping to spread the seed shadow of Ficus hondurensis; the ants removed the seeds either directly from fallen fruit or from the feces of frugivorous lizards, birds, and mammals. Winged queens and males of radoszkowskii were found in the Cumberland Valley of St. Vincent in mid-October. (Wilson 2003)

Identification
See the description in the nomenclature section.

Distribution
As presently conceived as one species, radoszkowskii ranges very widely through the New World tropics, from Jamaica, parts of the Lesser Antilles, and Central America south to Bolivia and to Argentina as far as Tucumán. It may prove to be a complex of sibling species, as noted in the Diagnosis (see description below). (Wilson 2003)

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Bolivia, Brazil, Colombia, Costa Rica, French Guiana, Greater Antilles, Guatemala, Guyana, Honduras, Jamaica, Lesser Antilles, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Venezuela.

Worker
Minor

Images from AntWeb
Major

Nomenclature

 *  radoszkowskii. Pheidole radoszkowskii Mayr, 1884: 35 (s.w.) FRENCH GUIANA. Senior synonym of acuta, australis, luteola, opacissima, paranana, parvinoda: Wilson, 2003: 221; of medialis: Longino, 2009: 70.
 * australis. Pheidole radowszkowskii r. australis Emery, 1890b: 50 (footnote) (s.w.) BRAZIL. Raised to species: Dalla Torre, 1893: 88. Subspecies of radoszkowskii: Emery, 1922e: 99. Junior synonym of radoszkowskii: Wilson, 2003: 221.
 * luteola. Pheidole radoszkowskii var. luteola Forel, 1893g: 406 (s.w.q.m.) ANTILLES. Junior synonym of radoszkowskii: Wilson, 2003: 221.
 * acuta. Pheidole radowszkowskii var. acuta Emery, 1894c: 154 (s.w.) BOLIVIA. Subspecies of radoszkowskii: Forel, 1909a: 258; Wheeler, W.M. 1925a: 21. Junior synonym of radoszkowskii: Wilson, 2003: 221.
 * opacissima. Pheidole radoszkowskii var. opacissima Forel, 1901e: 364 (s.w.) JAMAICA. Junior synonym of radoszkowskii: Wilson, 2003: 221.
 * parvinoda. Pheidole radoszkowskii r. parvinoda Forel, 1912f: 223 (s.w.) BRAZIL. Junior synonym of radoszkowskii: Wilson, 2003: 221.
 * medialis. Pheidole medialis Wilson, 2003: 208, figs. (s.w.) COSTA RICA. Junior synonym of radoszkowskii: Longino, 2009: 70.

Description
From Wilson (2003): A widespread abundant species of the diligens group characterized by the following combination of traits.

Major: reddish brown; pilosity sparse, entirely absent from mesosoma; patches of rugoreticulum present mesad to the eyes and anterior half of the pronotal dorsum; longitudinal carinulae cover the frontal lobes and extend most of the way posteriorly to the occiput; all of head, mesosoma, and waist foveolate and opaque; part of first gastral tergite shagreened and opaque; promesonotal profile 3-lobed in dorsal-oblique view.

Minor: reddish brown; carinulae absent or nearly so from body, including dorsum of head; all of head, mesosoma, and waist foveolate and opaque; part of first gastral tergite shagreened and opaque, remainder of gaster smooth and shiny.

P. radoszkowskii as conceived by me is highly variable, and may contain sibling species in addition to named infraspecific forms. (I have split off var. inversa and subsp. pugnax.) The synonymy I propose must therefore be considered provisional. In particular, there is wide variation among nest series in body color, from light to dark reddish brown. The form of the inner pair of hypostomal teeth ranges from long spikes to small denticles that do not reach beyond the hypostomal border; this variation may be bimodal. The amount of shagreening and hence degree of opacity differs from place to place and colony to colony. The extent of the rugoreticular patches also varies considerably. There is, finally, substantial variation in the thickness of the propodeal spine and petiolar node; for example, in the types of “variety acuta” these parts are noticeably thinner, and in “race australis” they are thicker. Only studies of geographicaland local variation will resolve the question of the nature of this variation and the possible existence of a sibling-species complex. Meanwhile, I have chosen the conservative measure of recognizing a single, widespread species. Otherwise, radoszkowskii can be separated from the three species it most resembles, Pheidole diligens, Pheidole inversa and Pheidole pugnax by the following combination of traits in the major: occiput foveolate and opaque; rugoreticulum present mesad to each eye; dorsum of promesonotum devoid of all pilosity; pronotum carinulate or rugoreticulate; anterior third to two-thirds of median strip of first gastral tergite shagreened; color usually reddish brown; 4 teeth present on hypostoma.

MEASUREMENTS (mm) Lectotype major: HW 1.08 HL 1.08, SL 0.72, EL 0.20, PW 0.54. Paralectotype minor: HW 0.54, HL 0.60, SL 0.66, EL 0.14, PW 0.34.

COLOR Major: body and mandibles medium reddish brown, antennae and legs brownish yellow.

Minor: body very dark, almost blackish brown, with a slight tinge of red; appendages medium brown. Other series placed in this species range from light to dark reddish brown.



'''Figure. Upper: lectotype, major. Lower: paralectotype, minor. Scale bars = 1 mm.'''

Type Material
From Wilson (2003): FRENCH GUIANA: Cayenne, collected by M. Jelski. - as reported in Wilson (2003)

Etymology
Named after O. Radoszkowsky, author of a list of the ants of Cayenne, French Guiana. (Wilson 2003)

References based on Global Ant Biodiversity Informatics

 * Antoniazzi R., R. N. S. L. Garoo, W. Dattilo, S. P. Ribeiro, and F. S. Neves. 2019. Ant species richness and interactions in canopies of two distinct successional stages in a tropical dry forest. The Science of Nature 106: 20
 * Bezdeckova K., P. Bedecka, and I. Machar. 2015. A checklist of the ants (Hymenoptera: Formicidae) of Peru. Zootaxa 4020 (1): 101–133.
 * Boer P. 2019. Ants of Curacao, species list. Accessed on January 22 2019 at http://www.nlmieren.nl/websitepages/SPECIES%20LIST%20CURACAO.html
 * Boscardin J., Correa Costa E., J. Garlet, and A. Fiorentini. 2013. Métodos de Captura para Formigas em Pré-plantio de Eucalyptus grandis. Floresta e Ambiente 20(3): 361-370.
 * Boscardin J., J. Garlet, and E. Correa Costa. 2012. Mirmecofauna epigéica (Hymenoptera: Formicidae) em plantios de Eucalyptus spp. (Myrtales: Myrtaceae) na região oeste do estado do Rio Grande do Sul, Brasil. Entomotropica 27(3): 119-128.
 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Coelho M. S., G. W. Fernandes, J. C. Santos, and J. H. C. Delabie. 2009. Ants (Hymenoptera: Formicidae) as bioindicators of land restoration in a Brazilian Atlantic forest fragment. Sociobiology 54(1): 51-63.
 * 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.
 * Delsinne T., Y. Roisin, and M. Leponce. 2007. Spatial and temporal foraging overlaps in a Chacoan ground-foraging ant assemblage. Journal of Arid Environments 71: 2944.
 * Drose W., L. R. Podgaiski, C. Fagundes Dias, M. de Souza Mendonca. 2019. Local and regional drivers of ant communities in forest-grassland ecotones in South Brazil: A taxonomic and phylogenetic approach. Plos ONE 14(4): e0215310.
 * Emery C. 1890. Studii sulle formiche della fauna neotropica. Bull. Soc. Entomol. Ital. 22: 38-8
 * Emery C. 1894. Studi sulle formiche della fauna neotropica. VI-XVI. Bullettino della Società Entomologica Italiana 26: 137-241.
 * Emery C. 1896. Formiciden, gesammelt in Paraguay von Dr. J. Bohls. Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere 9: 625-638.
 * Fernandes, P.R. XXXX. Los hormigas del suelo en Mexico: Diversidad, distribucion e importancia (Hymenoptera: Formicidae).
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Fleck M. D., E. Bisognin Cantarelli, and F. Granzotto. 2015. Register of new species of ants (Hymenoptera: Formicidae) in Rio Grande do Sul state. Ciencia Florestal, Santa Maria 25(2): 491-499.
 * Forel A. 1906. Fourmis néotropiques nouvelles ou peu connues. Annales de la Société Entomologique de Belgique 50: 225-249.
 * 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. Catálogo systemático da collecção de formigas do Ceará. Boletim do Museu Rocha 1(1): 62-69.
 * Forel A. 1908. Fourmis de Costa-Rica récoltées par M. Paul Biolley. Bulletin de la Société Vaudoise des Sciences Naturelles 44: 35-72.
 * Forel A. 1909. Ameisen aus Guatemala usw., Paraguay und Argentinien (Hym.). Deutsche Entomologische Zeitschrift 1909: 239-269.
 * 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.
 * Forel A. 1912. Formicides néotropiques. Part III. 3me sous-famille Myrmicinae (suite). Genres Cremastogaster et Pheidole. Mémoires de la Société Entomologique de Belgique. 19: 211-237.
 * Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
 * Gomes E. C. F., G. T. Ribeiro, T. M. S. Souza, and L. Sousa-Souto. 2014. Ant assemblages (Hymenoptera: Formicidae) in three different stages of forest regeneration in a fragment of Atlantic Forest in Sergipe, Brazil. Sociobiology 61(3): 250-257.
 * Gomez V. E. S., and G. Z. González. 2007. Catalogo de Las Hormigas Presentes en El Museo de Historia Natural de la Universidad del Cauca. Popayán : 1-58.
 * INBio Collection (via Gbif)
 * Kempf W. W. 1960. Insecta Amapaensia. - Hymenoptera: Formicidae (segunda contribuição). Studia Entomologica (n.s.)3: 385-400.
 * Kempf W. W. 1961. A survey of the ants of the soil fauna in Surinam (Hymenoptera: Formicidae). Studia Entomologica 4: 481-524.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Kusnezov N. 1952. El género Pheidole en la Argentina (Hymenoptera, Formicidae). Acta Zoologica Lilloana 12: 5-88.
 * Kusnezov N. 1953. La fauna mirmecológica de Bolivia. Folia Universitaria. Cochabamba 6: 211-229.
 * Leponce, M., L. Theunis, J.H.C. Delabie and Y. Roisin. 2004. Scale dependence of diversity measures in a leaf-litter ant assemblage. Ecography. 27:253-267.
 * Longino J. T. 2009. Additions to the taxonomy of New World Pheidole (Hymenoptera: Formicidae). Zootaxa 2181: 1-90.
 * Longino J. T. 2013. Ants of Nicargua. Consulted on 18 Jan 2013. https://sites.google.com/site/longinollama/reports/ants-of-nicaragua
 * Lopes D. T., J. Lopes, I. Cardoso do Nascimento, and J. H. Delabie. 2010. Epigeic ants diversity (Hymenoptera, Formicidae) in three environments in Mata dos Godoy State Park, Londrina, State of Paraná, Brazil. Iheringia, Sér. Zool., Porto Alegre, 100(1): 84-90.
 * Luederwaldt H. 1918. Notas myrmecologicas. Rev. Mus. Paul. 10: 29-64.
 * Maes, J.-M. and W.P. MacKay. 1993. Catalogo de las hormigas (Hymenoptera: Formicidae) de Nicaragua. Revista Nicaraguense de Entomologia 23.
 * Menozzi C. 1926. Neue Ameisen aus Brasilien. Zoologischer Anzeiger. 69: 68-72.
 * Nascimento Santos M., J. H. C. Delabie, and J. M. Queiroz. 2019. Biodiversity conservation in urban parks: a study of ground-dwelling ants (Hymenoptera: Formicidae) in Rio de Janeiro City. Urban Ecosystems https://doi.org/10.1007/s11252-019-00872-8
 * Pignalberi C. T. 1961. Contribución al conocimiento de los formícidos de la provincia de Santa Fé. Pp. 165-173 in: Comisión Investigación Científica; Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina) 1961. Actas y trabajos del primer Congreso Sudamericano de Zoología (La Plata, 12-24 octubre 1959). Tomo III. Buenos Aires: Librart, 276 pp.
 * Pires de Prado L., R. M. Feitosa, S. Pinzon Triana, J. A. Munoz Gutierrez, G. X. Rousseau, R. Alves Silva, G. M. Siqueira, C. L. Caldas dos Santos, F. Veras Silva, T. Sanches Ranzani da Silva, A. Casadei-Ferreira, R. Rosa da Silva, and J. Andrade-Silva. 2019. An overview of the ant fauna (Hymenoptera: Formicidae) of the state of Maranhao, Brazil. Pap. Avulsos Zool. 59: e20195938.
 * Radoszkowsky O. 1884. Fourmis de Cayenne Française. Trudy Russkago Entomologicheskago Obshchestva 18: 30-39.
 * Santos Lopes J. F., N. Martins dos Reis Hallack, T. Archanjo de Sales, M. Silva Brugger, L. F. Ribeiro, I. N. Hastenreiter, and R. da Silva Camargo. 2012. Comparison of the Ant Assemblages in Three Phytophysionomies: Rocky Field, Secondary Forest, and Riparian ForestA Case Study in the State Park of Ibitipoca, Brazil. Psyche doi:10.1155/2012/928371
 * Santos-Junior L. C., J. M. Saraiva, R. Silvestre, and W. F. Antonialli-Junior. 2014. Evaluation of Insects that Exploit Temporary Protein Resources Emphasizing the Action of Ants (Hymenoptera, Formicidae) in a Neotropical Semi-deciduous Forest. Sociobiology 61(1): 43-51
 * Suguituru S. S., M. Santina de Castro Morini, R. M. Feitosa, and R. Rosa da Silva. 2015. Formigas do Alto Tiete. Canal 6 Editora 458 pages
 * Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
 * Vittar, F., and F. Cuezzo. "Hormigas (Hymenoptera: Formicidae) de la provincia de Santa Fe, Argentina." Revista de la Sociedad Entomológica Argentina (versión On-line ISSN 1851-7471) 67, no. 1-2 (2008).
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Wetterer J. K., M. J. Liles, J. M. Sermeno, L. Serrano Cervantes, E. E. Echeverria, R. M. Estrada Hernandez, A. Henriquez, D. Perez, D. A. Sanchez Garcia, C. E. Gomez Peralta, R. Lopez Sorto, and G. Melendez. 2016. Predaceous fie ants (Hymenoptera: Formicidae) at sea turtle (Testudines: Cheloniidae) nestig beaches and hatcheries in El Salvador. Florida Entomologist 99(1): 106-109.
 * Wheeler W. M. 1905. The ants of the Bahamas, with a list of the known West Indian species. Bulletin of the American Museum of Natural History 21: 79-135.
 * Wheeler W. M. 1908. The ants of Jamaica. Bulletin of the American Museum of Natural History 24: 159-163.
 * Wheeler W. M. 1917. Jamaican ants collected by Prof. C. T. Brues. Bulletin of the Museum of Comparative Zoology 61: 457-471.
 * Wheeler W. M. 1942. Studies of Neotropical ant-plants and their ants. Bulletin of the Museum of Comparative Zoology 90: 1-262.
 * Wheeler, William Morton. 1911. Additions to the Ant-Fauna of Jamaica. Bulletin American Museum of Natural History. 30:21-29.
 * Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.
 * Zolessi L. C. de, Y. P. Abenante, and M. E. de Philippi. 1988. Lista sistematica de las especies de Formicidos del Uruguay. Comun. Zool. Mus. Hist. Nat. Montev. 11: 1-9.
 * Zolessi L. C. de; Y. P. de Abenante, and M. E. Philippi. 1989. Catálogo sistemático de las especies de Formícidos del Uruguay (Hymenoptera: Formicidae). Montevideo: ORCYT Unesco, 40 + ix pp.
 * de Almeida Soares S., Y. R. Suarez, W. D. Fernandes, P. M. Soares Tenorio, J. H. C. Delabie, and W. F. Antonialli-Junior. 2013. Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae) on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil. Rev. Bras. entomol. 57: 84-90
 * de Zolessi, L.C., Y.P. de Abenante and M.E. Philippi. 1987. Lista sistemática de las especies de formícidos del Uruguay. Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo 11(165):1-9
 * de Zolessi, L.C., Y.P. de Abenante and M.E. Phillipi. 1989. Catalago Systematico de las Especies de Formicidos del Uruguay (Hymenoptera: Formicidae). Oficina Regional de Ciencia y Technologia de la Unesco para America Latina y el Caribe- ORCYT. Montevideo, Uruguay