Wasmannia

Cuezzo and Calcaterra (2015) - The genus Wasmannia is mostly endemic to the Neotropics, with eleven species occurring from Argentina to Mexico. The little fire ant Wasmannia auropunctata is the most widely distributed species of the genus, being present from central-eastern Argentina north to the Caribbean and Bermuda (Wetterer & Porter, 2003). It has spread fairly recently throughout Pacific and Atlantic islands, and the Mediterranean region (e.g. Israel), and has become a serious pest in Hawaii and the Galapagos, disrupting agricultural practices and threatening wildlife (Foucaud et al., 2010).

Identification
Cuezzo and Calcaterra (2015) - All species of Wasmannia are small ants that can be differentiated from Blepharidatta and Allomerus by 1) having shallow, always well-developed antennal scrobes, 2) posterior margin of the vertex not pronounced as lobes or teeth (as in Blepharidatta), 3) petiolar node with a distinct anterior and dorsal face, and 4) irregularly striated head, at least in part, in full face view (Longino & Fernandez, 2007).

Besides these characters, the eight known species of Allomerus inhabit internal cavities of plants and have the propodeum unarmed to bidentate. The well-developed spines between the dorsal and posterior face of the propodeum, so typical of Wasmannia, are absent in Allomerus. The body of workers in Allomerus is always smooth and shining, resembling more a small Solenopsis than a worker of Wasmannia.

Argentina
Cuezzo et al. (2015) - The only species widely distributed in Argentina is the little fire ant, W. auropunctata, while the other four recorded species are rare and/or inconspicuous. The distribution of the W. auropunctata known from previous studies by Kusnezov (1952), Kempf (1972), Cuezzo (1998), and Fuentes et al.(1998) (Buenos Aires, Entre Ríos, Córdoba, Santa Fe, Corrientes, Chaco, Formosa, Tucumán, Jujuy, Salta and Misiones) was extended in this work to the provinces of Santiago del Estero, Catamarca, and La Rioja. W. auropunctata was not found in natural/native habitats of the Monte ecoregion, nor in the Patagonian ecoregion (L.A.C., unpublished data). The finding of W. auropunctata in Lozano (southern Buenos Aires province, 34º51´S) extends the known range 100 km further south than previously recorded in northeastern Buenos Aires (Reserva Natural Otamendi; 34º13’S) (Fuentes et al., 1998).

The other four species found in Argentina (W. sulcaticeps, W. rochai, W. williamsoni, and W. longiseta n. sp.) were much less common than W. auropunctata, and they were mostly present in natural and/or disturbed habitats. W. sulcaticeps was recorded for the first time for Corrientes and Catamarca provinces; it was previously known only from Buenos Aires, Santa Fé, Córdoba, Tucumán, Salta, and Jujuy provinces (Cuezzo, 1998; Vittar & Cuezzo, 2008). Although intensive surveys were conducted at multiple sites and in different biogeographic regions of Argentina, W. williamsoni was only found in central-eastern Argentina, suggesting it may be a relict endemic species. W. williamsoni was more common in the Parque Provincial Ernest Tornquist. This park protects several rare and endemic species of the Ventania mountainous system (Sellés-Martínez, 2001), which originates from the Tertiary period (around 22 million years ago). This could be the case of W. williamsoni, which is mostly restricted to this region and seems to show very small populations confined mainly to a specific habitat type. According to Longino & Fernández (2007), W. williamsoni and W. sulcaticeps are two related species that occur at the far southern limit of distribution of the genus and, as stated by Kusnezov (1952), could be the most primitive members of the genus, acting in the present as relicts. It is important to note that both species overlapped with W. auropunctata (more commonly in the lowlands) between approximately 400 and 1000 m elevation.

Nomenclature

 *  WASMANNIA [Myrmicinae: Blepharidattini]
 * Wasmannia Forel, 1893g: 383. Type-species: Tetramorium auropunctatum, by subsequent designation of Wheeler, W.M. 1911f: 174.
 * Wasmannia senior synonym of Hercynia: Brown, 1948d: 102.
 * HERCYNIA [junior synonym of Wasmannia]
 * Hercynia Enzmann, J. 1947a: 43. Type-species: Hercynia panamana (junior synonym of Tetramorium auropunctatum), by monotypy.
 * Hercynia junior synonym of Wasmannia: Brown, 1948d: 102.