Open Access
How to translate text using browser tools
1 March 2017 Distribution of Xenomyrmex floridanus (Hymenoptera: Formicidae) in Florida and the West Indies
James K. Wetterer
Author Affiliations +

Xenomyrmex floridanus Emery (Hymenoptera: Formicidae) is a small arboreal ant known only from peninsular Florida and the West Indies. Xenomyrmex floridanus colonies nest in plant cavities, particularly in hollow twigs and dead branches. I compiled and mapped >100 site records for X. floridanus, documenting the earliest known records for the 4 geographic areas where it occurs: peninsular Florida, the Bahamas, Cuba, and Jamaica. Records of X. floridanus range from Gainesville, Florida (29.7°N) in the north to Pedro Cross, Jamaica (18.9°N) in the south. Xenomyrmex floridanus shows striking evolutionary convergences in morphology and behavior with Monomorium floricola (Jerdon) (Hymenoptera: Formicidae), an Old World tramp ant species that has spread worldwide through human commerce. Both species are tiny, thin, and short-legged, a morphology that allows them to nest in very narrow plant cavities. In addition, both are slow moving and have an exceptional ability to cling to surfaces, a capacity that probably allows them to avoid being blown out of trees, even in high winds. Monomorium floricola has invaded Florida and the West Indies, where it may negatively impact X. floridanus populations. In red mangrove (Rhizophora mangle L.; Rhizophoraceae) in southeastern Florida, I found that X. floridanus is the most common native ant and M. floricola is the most common exotic ant.

Xenomyrmex floridanus Emery (Hymenoptera: Formicidae: Myrmicinae) is a small arboreal ant known only from peninsular Florida and the West Indies. Xenomyrmex floridanus colonies commonly nest in plant cavities, particularly in hollow twigs and dead branches (Creighton 1957). In the Florida Keys, X. floridanus colonies are common on red mangrove (Rhizophora mangle L.; Rhizophoraceae) tree islands (Simberloff & Wilson 1969; Cole 1983). In the Gainesville, Florida, area, X. floridanus colonies nest in sweetgum (Liquidambar styraciflua L.; Altingiaceae) trees (Van Pelt 1947). Here, I examine the biogeography of X. floridanus.

Forel (1884) established the genus Xenomyrmex, based on specimens of Xenomyrmex stolli Forel that Otto Stoll collected in Guatemala, co-inhabiting an oak gall with a carpenter ant (Camponotus abscicus Roger) colony. Forel (1884) assumed that X. stolli was probably a parasitic species, and named the genus Xenomyrmex, meaning “foreign ant.” Forel (1884: 55) wrote (in French): “This genus is nearest to Monomorium, which it closely resembles in habitus. Its petiole, however, is entirely different and is similar to the genus Pristomyrmex, which it otherwise does not at all resemble.”

Emery (1895) described Xenomyrmex stolli floridanus (= X. floridanus) based on specimens that Theodore Pergande collected from a twig of a yellow mastic tree (Sideroxylon foetidissimum Lam; Sapotaceae) in Lake Worth, Palm Beach Co., Florida. Junior synonyms include Xenomyrmex stolli cubanus Wheeler (from Cuba), Xenomyrmex stolli lucayanus Wheeler (from the Bahamas), and Xenomyrmex stolli rufescens Wheeler (from Florida).

The genus Xenomyrmex currently includes 4 other described species, all known only from Central America and/or Mexico: Xenomyrmex panamanus (Wheeler) (known from Panama), Xenomyrmex picquarti (Forel) (known from Costa Rica), Xenomyrmex skwarrae Wheeler (known from Guatemala and Mexico), and X. stolli (known from Guatemala and Mexico) (Kempf 1972; Bestelmeyer et al. 2000; Campbell et al. 2006; Pacheco & Mackay 2013). In addition, unidentified Xenomyrmex specimens have been recorded from South America: Brazil (Delabie & Nascimento 1998; Vasconcelos 2007), Colombia (SIB 2016), Paraguay (Wild 2007), and Peru (Wilson 1987). Because Xenomyrmex workers resemble small Monomorium and Solenopsis workers, they often may be misidentified (Wheeler 1931). It is therefore possible that unrecognized populations of Xenomyrmex are actually fairly widespread in South America.

Materials and Methods

Using published and unpublished records, I documented the known range of Xenomyrmex floridanus. I obtained unpublished site records from museum specimens in the collections of Archbold Biological Station (ABS), the Museum of Comparative Zoology (MCZ), and the Smithsonian Institution (SI). In addition, I used online databases with collection information on specimens by Antweb ( I obtained geo-coordinates for collection sites from published references, specimen labels, maps, or geography web sites (e.g., com and

In part to define better the geographic range of X. floridanus, I collected ants nesting inside dead twigs of red mangrove at sites along the east coast of Florida, north of the Florida Keys (in St. Johns, Volusia, Brevard, Indian River, St. Lucie, Martin, Palm Beach, Broward, and Miami-Dade counties) and on islands of the Bahamas (Grand Bahama, North Bimini, New Providence, and Half Moon Cay) and the Turks and Caicos Islands (Providenciales, North Caicos, Middle Caicos, and Grand Turk).


I collected Xenomyrmex floridanus nesting in the dead twigs and branches of red mangrove at 5 sites on 3 Bahamian islands (from north to south, geo-coordinates and collection date in parentheses):

  • Grand Bahama

    • Crabbing Beach (26.656°N, 77.980°W; 2-Jun-2015)

    • McLean's Town (26.644°N, 77.936°W; 2-Jun-2015)

  • North Bimini

    • North end of road (25.774°N, 79.263°W; 8-Jun-2015)

    • North end of lagoon (25.773°N, 79.261°W; 8-Jun-2015)

  • Half Moon Cay

    • Bonefish Lagoon (24.579°N, 75.950°W; 10-Aug-2015)

I also collected X. floridanus in red mangrove at 43 sites in 8 counties along the east coast of peninsular Florida (from north to south):

  • Volusia Co.

    • Daytona Beach, Manatee Island Park (29.219°N, 81.021°W; 31-Mar-2016)

    • Port Orange, Daniels Port Orange (29.147°N, 80.987°W; 19-Jun-2015)

    • Rose Bay, by fish camp (29.103°N, 80.972°W; 31-Mar-2016)

    • Spruce Creek, by boat ramp (29.083°N, 80.963°W; 31-Mar-2016)

    • New Smyrna Beach, South Causeway (29.027°N, 80.902°W; 31-Mar-2016)

  • Brevard Co.

    • Cape Canaveral, Manatee Sanctuary Park, (28.395°N, 80.619°W; 19-Jun-2015)

    • Melbourne Beach, Sebastian Inlet State Park (27.859°N, 80.452°W; 27-Feb-2016)

  • Indian River Co.

    • Wabasso Island, Environmental Learning Center (27.758°N, 80.415°W; 14-Mar-2015)

    • Vero Beach, Round Island Park (27.562°N, 80.329°W; 14-Mar-2015)

  • St. Lucie Co.

    • Indrio, Harbor Branch Oceanographic Institute (27.531°N, 80.349°W; 19-Feb-2015)

    • Fort Pierce, Jim Island (27.478°N, 80.314°W; 14-Mar-2015)

    • Fort Pierce, Bear Point Park (27.429°N, 80.281°W; 28 Nov-2014)

    • Fort Pierce, Blind Creek Park (27.378°N, 80.256°W; 14-Mar-2015)

  • Martin Co.

    • Joe's Point, Joe's Point Park (27.246°N, 80.194°W; 13-Nov-2015)

    • Jensen Beach, Indian Riverside Park (27.225°N, 80.212°W; 28-Mar-2015)

    • Stuart, Florida Oceanographic Coastal Center (27.216°N, 80.180°W; 21-Nov-2014)

    • Stuart, east end of A1A bridge (27.212°N, 80.184°W; 29-Nov-2015)

    • Stuart, Negro Cove (27.206°N, 80.170°W; 13-Nov-2015)

    • Seminole Shores, Bessie Cove (27.190°N, 80.162°W; 6-Dec-2015)

    • St. Lucie Inlet State Park, north end of Long Island (27.162°N, 80.167°W; 9-Apr-2015)

    • St. Lucie Inlet State Park, west side of Long Island (27.152°N, 80.162°W; 15-Nov-2014)

    • Port Salerno, Manatee Park (27.148°N, 80.196°W; 8-Dec-2015)

  • Palm Beach Co.

    • Tequesta, Coral Cove (26.963°N, 80.080°W; 3-Oct-2015)

    • Tequesta, south of Coral Cove (26.961°N, 80.079°W; 31-Dec-2015)

    • Jupiter, Jupiter Beach Park (26.940°N, 80.072°W; 12-Mar-2015)

    • Palm Beach Gardens, Village Square (26.837°N, 80.073°W; 19-Jun-2015, 25-Jan-2016)

    • Riviera Beach, Singer Island (26.816°N, 80.038°W; 12-Mar-2015)

    • Palm Beach, Bingham Island (26.674°N, 80.044°W; 29-Dec-2015)

    • Boca Raton, Gumbo Limbo Nature Center (26.367°N, 80.071°W; 26-Feb-2015)

  • Broward Co.

    • Pompano Beach, Bay Drive (26.254°N, 80.084°W; 1-Nov-2015)

    • Fort Lauderdale, English Park (26.139°N, 80.116°W; 27-Feb-2015)

    • Dania, by fishing charter (26.048°N, 80.115°W; 14-Nov-2015)

    • Hollywood, West Lake Park (26.040°N, 80.118°W; 14-Nov-2015)

    • Hollywood, Ann Kolb Center, Observation Trail (26.040°N, 80.122°W; 24-Apr-2016)

    • Hollywood, Ann Kolb Center, Mudflat Trail (26.036°N, 80.121°W; 24-Apr-2016)

    • Hollywood, Lake Forest Park (26.035°N, 80.117°W; 14-Nov-2015)

    • Hollywood, Holland Park (26.019°N, 80.118°W; 14-Nov-2015)

  • Miami-Dade Co.

    • Aventura, NE 207th St. (25.968°N, 80.132°W; 21-Feb-2016)

    • North Miami Beach, SW Maule Lake (25.929°N, 80.150°W; 24-Apr-2016)

    • North Miami Beach, Oleta River State Park (25.916°N, 80.128°W; 20-Feb-2016)

    • Virginia Key, Miami Seaquarium (25.733°N, 80.167°W; 21-Feb-2016)

    • Key Biscayne, No Name Harbor (25.676°N, 80.161°W; 21-Feb-2016)

    • Homestead, Bayfront Park (25.463°N, 80.346°W; 20-Feb-2016)

I also collected X. floridanus nesting in black mangrove, Avicennia germinans (L.) (Acanthaceae), at 1 site where red mangrove was absent:

  • Martin Co.

    • Port Salerno, Cove Road Park (27.149°N, 80.168°W; 7-Nov-2015)

In total, I compiled and mapped >100 X. floridanus site records (Fig. 1), documenting the earliest known record for 4 geographic areas (Table 1): Bahamas (Wheeler 1905, 1931; Deyrup 1994; Deyrup et al. 1998), Cuba (Wheeler 1931; Fontenla Rizo 1993a,b; Fontenla 1999; Portuondo Ferrer & Fernández Triana 2004; Portuondo & Fontenla Rizo 2005; Reyes 2005;, Florida (Wheeler 1931; Creighton 1957; Van Pelt 1947, 1958; Simberloff & Wilson 1969; Simberloff 1976; Deyrup et al. 1988; Ferster & Prusak 1994; Valles et al. 2007; Moreau & al 2014;; ABS), and Jamaica (; Table 1). Known records of X. floridanus ranged from Gainesville, Florida (29.7°N; Valles et al. 2007), in the north to Pedro Cross, Jamaica (18.9°N; Table 1), in the south.

Whereas Deyrup et al. (1989) listed X. floridanus from 10 counties in Florida, I found published and unpublished records of X. floridanus from 18 counties in Florida: Alachua, Brevard, Charlotte, Collier, Desoto, Highlands, Hillsborough, Lake, Lee, Marion, Miami-Dade, Monroe, Orange, Palm Beach, Pinellas, Polk, Sarasota, and Volusia. In addition, I collected the first records of X. floridanus from 4 additional counties: Broward, Indian River, Martin, and St. Lucie (see list above), bringing the total to 22 counties in Florida.

Fig. 1.

Known site records of Xenomyrmex floridanus.


Table 1.

Earliest known records for Xenomyrmex floridanus.


North of Volusia County, red mangroves are rare. I did not find X. floridanus at the only red mangrove site I surveyed in St. Johns County (St. Augustine, Fish Island Marina, 29.8705°N, 81.3025°W; 24-Jul-2016), where I only found M. floricola. I did not find any red mangroves at 2 sites in Flagler County dominated by black mangrove: Betty Steflik Memorial Preserve and Gamble Rogers Memorial State Recreational Area.


Xenomyrmex floridanus has widespread records from peninsular Florida, the Bahamas, and Cuba, plus 1 record from Jamaica (Fig. 1). The high concentration of X. floridanus records along the east coast of peninsular Florida (Fig. 1) is primarily due to my collecting ants nesting in red mangrove, a tree species restricted to brackish habitats. Although X. floridanus colonies nest in many tree species, it appears that red mangrove provides an important habitat for this species. In my surveys of red mangrove in southeastern Florida and the Bahamas, X. floridanus was the native ant species that I most commonly collected.

Concerning X. floridanus, Wheeler (1905) wrote that “the habits of the workers resemble those of Monomorium floricola, so far as could be ascertained by hasty observation in the field.” Monomorium floricola (Jerdon) is native to the Old World, but has been transported around the world through human commerce (Wetterer 2010) and is the most common exotic ant I collected in red mangrove in Florida. My own observations confirm Wheeler's (1905) supposition that X. floridanus and M. floricola show evolutionary convergence in morphology and behavior. Both species are tiny, thin, and short-legged, a morphology that allows them to nest in very narrow plant cavities, such as inside the hollow dead twigs of red mangrove. Both X. floridanus and M. floricola are slow moving and have an exceptional ability to cling tenaciously to surfaces. As a result, both species can be difficult to collect off twigs and branches using an aspirator and are hard to dislodge through vegetation beating. The ability to grip onto surfaces probably allows these arboreal ants to avoid being blown out of trees, even in high winds. This trait should be particularly important for ants living in red mangrove growing in brackish water, where falling out of the tree would mean almost certain death.

Whereas X. floridanus is extremely common in red mangroves of southeast Florida, additional research is needed to determine whether the same is true in the Bahamas, Cuba, and Jamaica. It is not known whether X. floridanus possesses any special adaptations for living in red mangroves, such as high salt tolerance, or whether the prevalence of hollow spaces in dead twigs of red mangroves may be indicative of a myrmecophyte that benefits from the presence of ants. The close similarity in the behavior and ecology of X. floridanus and M. floricola suggests that these 2 species may be important competitors in areas where M. floricola invades. Monomorium floricola colonies can grow to an enormous size with thousands of workers and dozens of queens (personal observation), giving them a numerical advantage over X. floridanus. Evaluating whether M. floricola has a significant impact on X. floridanus populations in Florida, the Bahamas, or elsewhere would require further research.


I thank M. Wetterer for comments on this manuscript; S. Hendry, A. Schaffner, A. Inamoto, A. Ardelean, A. Ridgeway, B. Liddell, C. Danley, C. Olbrych, D. Arrieta, D. Brothers, G. Kramer, J. Herr, K. Kelly, L. Feliciano, M. Merritt, S. Crary, S. Groth, T. Holmes, and T. Bertolami for field assistance; M. Deyrup (ABS), S. Cover (MCZ), and T. Schultz (SI) for help with their respective ant collections; W. O'Brien for GIS help; D. P. Wojcik and S. D. Porter for compiling their valuable FORMIS bibliography; and Florida Atlantic University for financial support.

References Cited


Bestelmeyer BT, Alonso L, Snelling RR. 2000. The ants (Hymenoptera: Formicidae) of Laguna del Tigre National Park, Petén, Guatemala. RAP Bulletin of Biological Assessment 16: 75–83. Google Scholar


Campbell CM, Pacheco JA, Mackay WP. 2006. An introduction to the new world ant Xenomyrmex (Hymenoptera: Formicidae). p. 105 In 3rd Annual SACNAS National Conference, 26–28 October 2006, Tampa, FL. Google Scholar


Cole BJ. 1983. Assembly of mangrove ant communities: patterns of geographical distribution. Journal of Animal Ecology 52: 339–347. Google Scholar


Creighton WS. 1957. A study of the genus Xenomyrmex (Hymenoptera, Formicidae). American Museum Novitates 1843: 1–14. Google Scholar


Delabie JHC, Nascimento IC do. 1998. As formigas do município de Ilhéus (Insecta: Hymenoptera: Formicidae). Especiaria 1: 133–152. Google Scholar


Deyrup M. 1994. Biogeographical survey of the ants of the island of San Salvador, Bahamas, pp. 21–28 In Kass LB. [ed.]. Proceedings of the 5th Symposium on the Natural History of the Bahamas, Bahamian Field Station, San Salvador, Bahamas. Google Scholar


Deyrup MA, Carlin N, Trager J, Umphrey G. 1988. A review of the ants of the Florida Keys. Florida Entomologist 71: 165–166. Google Scholar


Deyrup M, Johnson C, Wheeler GC, Wheeler J. 1989. A preliminary list of the ants of Florida. Florida Entomologist 72: 91–101. Google Scholar


Deyrup M, Davis L, Buckner S. 1998. Composition of the ant fauna of three Bahamian islands, pp. 23–31 In Proceedings of the 7th Symposium of Natural History. Bahamas, Bahamian Field Station, San Salvador, Bahamas. Google Scholar


Emery C. 1895. Beiträge zur Kenntniss der nordamerikanischen Ameisenfauna. (Schluss). Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere 8: 257–360. Google Scholar


Ferster B, Prusak Z. 1994. A preliminary check-list of the ants (Hymenoptera: Formicidae) of Everglades National Park. Florida Entomologist 77: 508–512. Google Scholar


Fontenla Rizo JL. 1993a. Composición y estructura de comunidades de hormigas en un sistema de formaciones vegetales costeras. Poeyana 441: 1–19. Google Scholar


Fontenla Rizo JL. 1993b. Mirmecofauna de Isla de la Juventud y de algunos cayos del archipiélago cubano. Poeyana 444: 1–17. Google Scholar


Fontenla JL. 1999. Mirmecofauna del Jardín Botánico Nacional. Cocuyo 8: 8–10. Google Scholar


Forel A. 1884. Études myrmécologiques en 1884 avec une description des organes sensoriels des antennes. Bulletin de la Société Vaudoise des Sciences Naturelles 20: 316–380. Google Scholar


Kempf WW. 1972. Catálogo abreviado das formigas da região neotropical (Hymenoptera: Formicidae). Studia Entomologica 15: 3–344. Google Scholar


Moreau CS, Deyrup MA, Davis LR Jr . 2014. Ants of the Florida Keys: species accounts, biogeography, and conservation (Hymenoptera: Formicidae). Journal of Insect Science 14(295): 2014; DOI: 10.1093/jisesa/ieu157. Google Scholar


Pacheco JA, Mackay WP. 2013. The systematics and biology of the New World thief ants of the genus Solenopsis (Hymenoptera: Formicidae). Edwin Mellen Press, Lewiston, New York. Google Scholar


Portuondo Ferrer E, Fernández Triana JL. 2004. Biodiversidad del orden Hymenoptera en los Macizos Montañosos de Cuba Oriental. Boletín de la Sociedad Entomológica Aragonesa 35: 121–136. Google Scholar


Portuondo Ferrer E, Fontenla Rizo JL. 2005. Appendix 8, pp. 185–187 In Fong, A, Maceira D, Alverson WS, Shopland JM [eds]. Cuba: Siboney-Juticí. Rapid Biological Inventories Report 10. The Rapid Biological Inventories. Google Scholar


Reyes, J.L. 2005. Inventario de la coleccion de hormigas (Hymenoptera: Formicidae) del Centro Oriental de Ecosistemas y Biodiversidad, Santiago de Cuba, Cuba. Boletín de la Sociedad Entomológica Aragonesa 36: 279–283. Google Scholar


SIB (Sistema de Información sobre Biodiversidad de Colombia) 2016.  Google Scholar


Simberloff DS. 1976. Species turnover and equilibrium island biogeography. Science 194: 572–578. Google Scholar


Simberloff DS, Wilson EO. 1969. Experimental zoogeography of islands: the colonization of empty islands. Ecology 50: 278–296. Google Scholar


Valles SM, Strong CA, Oi DH, Porter SD, Pereira RM, Vander Meer RK, Hashimoto, Y, Hooper-Bùi LM, Sánchez-Arroyo H, Davis T, Karpakakunjaram V, Vail KM, Graham LC, Briano JA, Calcaterra LA, Gilbert LE, Ward R, Ward K, Oliver JB, Taniguchi G, Thompson DC. 2007. Phenology, distribution, and host specificity of Solenopsis invicta virus-1. Journal of Invertebrate Pathology 96: 18–27. Google Scholar


Van Pelt AF. 1947. Ants of the Gainesville region with special reference to ecology and taxonomy (Hymenoptera: Formicidae). M.S. Thesis, University of Florida. Google Scholar


Van Pelt AF. 1958. The ecology of the ants of the Welaka Reserve, Florida (Hymenoptera: Formicidae). Part II. Annotated list. American Midland Naturalist 59: 1–57. Google Scholar


Vasconcelos HL. 2007. Padrões de distribuição de formigas na várzea amazônica. O Biologico 69: 135–137. Google Scholar


Wetterer JK. 2010. Worldwide spread of the flower ant, Monomorium floricola (Hymenoptera: Formicidae). Myrmecological News 13: 19–27. Google Scholar


Wheeler WM. 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. Google Scholar


Wheeler WM. 1931. Neotropical ants of the genus Xenomyrmex Forel. Revista de Entomologia (Rio de Janeiro) 1: 129–139. Google Scholar


Wild AL. 2007. A catalogue of the ants of Paraguay (Hymenoptera: Formicidae). Zootaxa 1622: 1–55. Google Scholar


Wilson EO. 1987. The arboreal ant fauna of Peruvian Amazon forests: a first assessment. Biotropica 19: 245–251. Google Scholar
James K. Wetterer "Distribution of Xenomyrmex floridanus (Hymenoptera: Formicidae) in Florida and the West Indies," Florida Entomologist 100(1), 5-8, (1 March 2017).
Published: 1 March 2017
geographic range
mangle rojo
native range
rango geográfico
rango nativo
Back to Top