Current View: All Antweb
Change View
Cite this page

Citing AntWeb


To cite this page, please use the following:

· For print: . Accessed

· For web:

Species: Eurhopalothrix floridana   Brown & Kempf, 1960 

Download Data

Taxonomic History (provided by Barry Bolton, 2019)

Eurhopalothrix floridana Brown & Kempf, 1960 PDF: 207, fig. 34 (w.) U.S.A. Nearctic. AntCat AntWiki HOL

Taxonomic history

Longino, 2013 PDF: 119 (q.).


Eurhopalothrix floridana is a small (~2.5 mm) brownish red ant with a triangular head, 7-segmented antennae, deep antennal scrobes, small eyes, triangular mandibles, distinctive appressed spatulate hairs and no spongiform. Although described from Florida relatively recently, there is broad speculation that it is not native to Florida or any other part of North America north of Mexico (Brown & Kempf, 1960; Deyrup, 1991; Deyrup et al., 2000; Deyrup et al., 1997). Eurhopalothrix species are predatory, and observations of one species suggest that these ants may be somewhat specialized predators of termites (Wilson & Brown, 1985.


  Geographic regions (According to curated Geolocale/Taxon lists):
    Americas: Dominican Republic, Puerto Rico, United States
  Biogeographic regions (According to curated Bioregion/Taxon lists):
    Nearctic, Neotropical
  Native to (according to species list records):
    Nearctic, Neotropical bioregions

Distribution Notes:

Florida, Puerto Rico, Dominican Republic.


Deyrup et al. (1997)argue that E. floridana is actually fairly common in Florida, and are skeptical that it could have remained undetected for so long if the species was native. They point out that the species is unknown from the West Indies, from where almost all of Florida’s tropical ant fauna is derived. The authors also present arguments for its status as a native species, including its cryptic nature, low tolerance for disturbed habitats and capacity for surviving in xeric conditions. The discovery of a specimen from Key West collected in 1887 makes for inconclusive evidence of native status, as Key West was a thriving commercial port during that time which received many shipments of exotic horticultural plants from Mexico.Add your content here.


Diagnosis among workers of introduced and commonly intercepted ants in the United States. Head shape triangular. Antenna 7-segmented. Antennal club 2-segmented. Antennal scapes not conspicuously short; easily extended beyond eye level. Antennal scrobe present and deeply excavated. Eyes small (less than 5 facets), situated on upper margin of scrobe. Frontal lobes do not obscure face outline between mandible and eye. Posterolateral corners of head unarmed, without spines. Mandibles triangular. Pronotal spines absent. Propodeum armed with spines. Waist 2-segmented. Spongiform not attached to any portion of waist. Color brownish red. Abundant ground pilosity characterized by small whitish appressed spatulate hairs.

Among introduced and commonly intercepted ants of the United States, Eurhopalothrix floridana is most likely to be confused with Pyramica species that have triangular mandibles, such as P. margaritae and P. membranifera. However, E. floridana is easily separated from these by its 7-segmented antennae (vs. 6-segmented in Pyramica), eye that is situated on the upper margin of the antennal scrobe (vs. lower margin in Pyramica), and lack of spongiform on either waist segment.

Among the New World species in general, E. floridana has a double mandibular tooth row, like E. gravis. Unlike E. gravis, it has a reduced number of spatulate setae. Florida populations have a single pair on the posterior vertex margin. Populations in Puerto Rico and Dominican Republic may have a posteromedian rectangle of 2 pairs. The promesonotum has a full complement of 3 pairs. Eurhopalothrix vulcan from Guatemala and E. sepultura from southern Mexico are similar, but have more than 2 pairs of erect setae on the face. Eurhopalothrix apharogonia from El Salvador is similar but has a much narrower head and only 1 pair of erect setae on the mesosoma.


Longino (2013): Deyrup et al. (1997) reviewed the status of E. floridana in Florida and described the male. The species was moderately abundant in hardwood hammocks throughout peninsular Florida but did not extend into the western panhandle. They speculated that the species could be exotic in Florida, and referred to a personal communication from W. L. Brown that the species occurred in Mexico. I have seen no material to verify the occurrence in Mexico, but J. Wetterer collected specimens on Mona Island, Puerto Rico, and D. Lubertazzi collected specimens along a roadside in the Dominican Republic. These specimens are nearly identical to specimens from Florida, although there is some variation in number of erect setae. On the two Mona Island specimens, one has a cluster of 2 setae on the face and one has 3. Both have the full complement of 6 setae on the promesonotum. On the two Dominican Republic specimens, one has a cluster of 3 setae on the face, 3 setae down one side of the promesonotum, and 1 seta on the opposite side, paired with the posteriormost. The other one has no setae on the face and 2 on the mesonotum. How much these patterns are due to seta loss is unknown, but the base number could be a cluster of 4 on the face, like E. apharogonia, and 6 on the promesonotum. The biogeographic history of this species, in Florida and elsewhere, remains enigmatic.


Brown, W.L., Jr. & Kempf, W.W. (1960) A world revision of the ant tribe Basicerotini (Hym. Formicidae). Stud. Entomol., (n.s.)3, 161-250.

Deyrup, M. (1991) Exotic ants of the Florida keys (Hymenoptera: Formicidae). In: Eshbaugh, W.H. (Ed.) Proceedings of the 4th symposium on the natural history of the Bahamas. Bahamian Field Station, San Salvador, Bahamas, pp. 15-22.

Deyrup, M., Davis, L. & Cover, S. (2000) Exotic ants in Florida. Trans. Am. Entomol. Soc., 126, 293-326.

Deyrup, M., Johnson, C. & Davis, L. (1997) Notes on the ant Eurhopalothrix floridana, with a description of the male (Hymenoptera: Formicidae). Entomol. News, 108, 183-189.

Longino, J. T. (2013) A review of the Central American and Caribbean species of the ant genus Eurhopalothrix Brown and Kempf, 1961 (Hymenoptera, Formicidae), with a key to New World species. Zootaxa, 3693, 101-151.

Wilson, E.O. & Brown, W.L., Jr. (1985) Behavior of the cryptobiotic predaceous ant Eurhopalothrix heliscata, n. sp. (Hymenoptera: Formicidae: Basicerotini). Insect. Soc., 31, 408-428.

Specimen Habitat Summary

Found most commonly in these habitats: 1 times found in riparian woodland, 1 times found in roadside, secondary scrub, 1 times found in pine forest, 1 times found in swampy riparian woodland, 1 times found in xeric coastal hammock, 1 times found in Palm Hammock.

Found most commonly in these microhabitats: 2 times ex sifted leaf litter, 2 times Sifted litter, 1 times in soil at base of stump, 1 times pine litter, 1 times litter sample, 1 times leaf litter.

Collected most commonly using these methods: 1 times winkler, 1 times berlese funnel, 1 times direct collection, 1 times sample 625, 1 times Berlese.

Elevations: collected from 20 - 60 meters, 30 meters average

Type specimens: Holotype: fmnhins0000047628

See something amiss? Send us an email.