Response to Genovesi et al.: Ant biosurveillance should come before invasion.

Menchetti et al. respond to the letter of Genovesi et al. and contribute new records of the red imported fire ant in Sicily.

Nomenclatural changes on some Mediterranean Aphaenogaster Mayr, 1853 taxa (Hymenoptera, Formicidae).

The ant genus Aphaenogaster Mayr, 1853 is especially diverse in the West-Palearctic region, where its taxonomy is still problematic for several groups. Among other issues, there is a redundancy of valid taxa compared to the number of species whose validity is currently sustained by any evidence. Names that do not represent taxa with clearly defined identities complicate specimen identification and add confusion to biodiversity databases and checklists. Based on a review of the available literature information on several taxa, and the study of both type and non-type material, the following taxonomic changes are proposed: i) A. mauritanica Dalla Torre, 1893 should be considered a senior synonym of A. gibbosa homonyma Emery, 1921 syn. nov. and of A. foreli Cagniant, 1996 syn. nov. (the Maghrebian populations of the pallida group hitherto considered to represent A. foreli should be attributed to A. dulcineae Emery, 1924); ii) A. pallida (Nylander, 1849) should be considered a senior synonym of A. leveillei Emery, 1881 syn. nov. and of A. leveillei laurenti Santschi, 1939 syn. nov.; iii) A. sangiorgii (Emery, 1901) should be considered a senior synonym of A. finzii Müller, 1921 syn. nov. and A. radchenkoi Kiran & Tezcan, 2008 syn. nov.; iv) A. sardoa Mayr, 1853 should be considered a senior synonym of A. sardoa ujhelyii Szabó, 1910 syn. nov. and A. sardoa anoemica Santschi, 1910 syn. nov.; v) A. subterraneosplendida André, 1883 should be considered a senior synonym of A. sicula Emery, 1908 syn. nov.; vi) A. subterraneoides Emery, 1881 should be considered a senior synonym of A. subterraneoides armeniaca Arnol'di, 1968 syn. nov. These changes will reduce the gap between nomenclature and actual understanding of species diversity, while synonymized names may be resurrected if supporting evidence is discovered.

The invasive ant Solenopsis invicta is established in Europe.

The red imported fire ant (Solenopsis invicta) is classified as one of the worst invasive alien species1 and as the fifth costliest worldwide2, impacting ecosystems, agriculture and human health3. We report the establishment of S. invicta in Europe for the first time, documenting a mature population in Sicily. We use genetic analyses to assess its putative origin, as well as wind tracking and species distribution modelling to predict its potential range on the continent. We show that half of the urban areas in Europe are already suitable and that climate warming expected under current trends will favor the expansion of this invasive ant.

Unrecognized for centuries: distribution and sexual caste descriptions of the West European Aphaenogaster species of the subterranea group (Hymenoptera, Formicidae).

There are only two Aphaenogaster species from the subterranea group in the western Mediterranean: A.ichnusa Santschi, 1925, from south-western Europe, and A.subterranea (Latreille, 1798), also occurring in central and eastern Europe. Historically, the two species have been widely misunderstood: A.ichnusa was long considered a Sardinian endemic subspecies of A.subterranea, while its continental populations were misidentified as A.subterranea s. str. Recently, A.ichnusa was elevated to species rank and its worker caste was redescribed with that of A.subterranea, allowing for their correct identification. Yet their distribution was documented in detail only for France and Sardinia. Furthermore, no morphological characters were described to distinguish the males and queens of the two species. By investigating private and museum collections, 276 new records of A.ichnusa are provided here and 154 of A.subterranea from the western Mediterranean. Additionally, qualitative and quantitative morphological characters were combined to identify their males and queens. We present the new southernmost, easternmost, and westernmost distribution limits for A.ichnusa. Based on our results, this species is widely distributed in Italy and Catalonia (Spain), also occurring on several Mediterranean islands, avoiding areas with continental climate and high altitudes. Sicily is the only island to host the less thermophilous A.subterranea, which otherwise extends westward to Galicia (Spain). Sympatric occurrence is not rare along the contact zone. Additional natural history observations are reported regarding foraging habits, associated myrmecophiles, habitat preferences, and colony structure in the two species.