Nylanderia pubens

This ant belongs to a species complex that contains a number of morphologically similar species.

Identification
Good luck! As per Gotzek et al (2012), the genus Nylanderia has a long history of taxonomic uncertainty in North America largely due to a lack of distinctive morphological characters in the worker caste (also see the biology section below).

Identification Keys including this Taxon

 * Key to Nearctic Nylanderia workers
 * Key to Nearctic Nylanderia males

Distribution
Possibly restricted to the Caribbean region.

In Florida, where this is an introduced ant, it has had a foothold in Coral Gables, Dade County, for many years, but does not seem to be spreading rapidly. It is abundant on the campus of the University of Miami, where it forages on side walks and runs up and down tree trunks. Pest status: so far, this is a minor and localized pest. There are two reports of large infestations in buildings (Klotz et al. 1995). First published Florida record: Trager 1984; earlier specimens: 1953. (Deyrup, Davis & Cover, 2000.)

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Anguilla, Barbados, Cuba, Dominican Republic, Ecuador, Guadeloupe, Haiti, Lesser Antilles, Puerto Rico.

Biology
The following text and map are from Gotzek et al. (2012). References that were indicated but removed from the text are stated in the original publication:

There has been widespread misidentification of Nylanderia fulva. Within museum collections, misidentifications are common given the morphological similarities of the workers within the genus overall, as well as because of uncertainties regarding species boundaries.

Given the uncertainty of worker based identifications of N. fulva and N. pubens most publications that involve either of these species are suspect; they may not involve the species listed in the publication, including the possibility that they are neither N. fulva nor N. pubens and are an entirely different Nylanderia species. It appears at this time that N. pubens is restricted to the Caribbean region. This species has been reported to be relatively to be relatively common in southern Florida in the 1950’s –1970’s, where it was also most recently found in 1994 (M. Deyrup, pers. comm. to JSL). It is not known whether these populations still persist today. Since we show that samples from northern Florida initially considered to be N. cf. pubens are actually N. fulva and given the invasive nature of N. fulva, we hypothesize that most or even all alleged occurrences of N. pubens in Florida are misidentified N. fulva. This would not be surprising, since the distribution is solely based on worker identifications (D. Oi, pers. comm. to DG). We also suspect that N. pubens may not have good invasive capabilities compared to N. fulva, given the currently rapidly expanding distribution of N. fulva in the United States and lack of N. pubens in our samples from northern Florida. It will require much better sampling of molecular data or male samples from throughout Florida to test our hypothesis. Currently, the Caribbean is likely the only place where N. fulva and N. pubens are sympatric and therefore the only region where identifications of workers will be difficult. If we are correct concerning the distribution and inability of N. pubens to become a pest, then the population explosions attributed to N. pubens that plagued the Caribbean from 19th century Bermuda to the recent outbreak on St. Croix and in southern Florida may very well have been N. fulva instead of N. pubens. Nylanderia fulva is known to be an invasive ant, most recently from Colombia where an outbreak occurred after this species was apparently introduced to control leafcutter ants and venomous snakes.

Nomenclature

 *  pubens. Prenolepis fulva r. pubens Forel, 1893g: 338 (w.q.m.) ANTILLES. Combination in Paratrechina (Nylanderia): Emery, 1925b: 222; in Nylanderia: Kempf, 1972a: 167; in Paratrechina: Trager, 1984b: 143; in Nylanderia: LaPolla, Brady & Shattuck, 2010a: 127. Junior synonym of fulva: Creighton, 1950a: 406. Revived from synonymy and raised to species: Trager, 1984b: 143.