Three endemic Aphaenogaster from the Siculo-Maltese archipelago and the Italian Peninsula: part of a hitherto unrecognized species group from the Maghreb? (Hymenoptera: Formicidae: Myrmicinae)

Abstract

<jats:title>Abstract</jats:title> <jats:p>More than 100 years ago, the Italian myrmecologist Carlo Emery described two endemic Sicilian ants: <jats:italic>Aphaenogaster sicula</jats:italic> Emery, 1908, which he originally considered a subspecies of <jats:italic>A. crocea</jats:italic> André, 1881, and <jats:italic>A. fiorii</jats:italic> Emery, 1915 stat. nov., which he believed was a subspecies of <jats:italic>A. gibbosa</jats:italic> (Latreille, 1798). Males of the two species and the queen of <jats:italic>A. fiorii</jats:italic> were never described. The scarcity of information contained in the original description led to several misunderstandings by subsequent authors: for example, <jats:italic>A. sicula</jats:italic> was later elevated to species-rank on the basis of misidentified material of <jats:italic>A. fiorii</jats:italic> stat. nov. We redescribe the two species, adding the descriptions of their missing castes and designating their lectotypes. We also describe a third related species of the genus: <jats:italic>A. trinacriae</jats:italic> sp. nov. from Sicily. The ecology and distribution of the three are illustrated. Their relationship with the other congeneric species of the Mediterranean basin is discussed considering the morphology of all three castes, with attention to the often-overlooked males. Despite the fact that <jats:italic>A. fiorii</jats:italic> and <jats:italic>A. sicula</jats:italic> were lately believed to be close relatives of <jats:italic>A. subterranea</jats:italic> (Latreille, 1798), the morphological elements available suggest that they probably belong to a separate, hitherto unrecognized clade from the Maghreb (North-Western Africa), together with <jats:italic>A. trinacriae</jats:italic> sp. nov.</jats:p>

Aphaenogaster finzii Müller, 1921, a trans-Ionian species new to Italy (Hymenoptera, Formicidae)

“…Furthermore, many Mediterranean species of the genus Aphaenogaster have often been confused with each other as the genus has sometimes been overlooked by specialists (e.g. see Boer 2013, Alicata & Schifani 2019. Although A. finzii is very easily distinguished among the congeneric Italian species, it cannot be excluded that it may still have been confused with others in the past.…”

“…The Italian ant fauna currently counts about 270 taxa (Antweb, 2019), including many only added during the last two decades, as a result of either taxonomic (Rigato 1999, Radchenko et al 2006, Csősz et al 2007, Schulz et al 2007, Elmes et al 2008, Steiner et al 2010, Seifert 2012, Rigato 2011, Wagner et al 2017, Steiner et al 2018, Alicata & Schifani 2019 or faunistic investigations (Bonelli et al 2004, Rigato & Toni 2011, Schifani 2017, Schifani & Alicata 2018. Additional diversity is expected to be discovered, especially from the South of the country, which is less explored.…”

“…legs length, short scapes, relatively small eyes) immediately distinguish them as members of the A. pallida group (sensu Boer 2013). Müller (1921) emphasizes also a similarity to A. subterranea (Latreille, 1798), especially regarding the size and shape of the propodeal spines, but members of the A. subterranea group have a much deeper metanotal groove (Alicata & Schifani 2019) in addition to a usually more developed sculpture and shorter hairs on the mesosoma. Among the Italian representatives of the A. pallida group, A. finzii workers can be easily separated from A. pallida (Nylander, 1849), present in Sicily and Southern Italy, due to its lack of propodeal spines, and from A. dulciniae, only present in Liguria, due to their different mesosoma (including shorter spines) and head shape.…”

“…The shape of mesosoma is an unreliable and misleading character for workers identification in some ant species (e.g. Camponotus lateralis (Olivier, 1792), see Seifert 2018) but proved to be one of the most reliable and easy characters in some recently revised species of Aphaenogaster Mayr, 1853 (Alicata & Schifani 2019). Aphaenogaster finzii workers are also distinguished by a larger size and significantly developed, usually horizontal, propodeal spines when compared to most of the similar species of the Balkans (Agosti and Collingwood 1978).…”

Exotic Ants (Hymenoptera, Formicidae) Invading Mediterranean Europe: a Brief Summary over About 200 Years of Documented Introductions

“…For example, the status of Cardiocondyla mauritanica Forel, 1890 in Sicily is currently dubious (Schifani & Alicata, 2018): it is considered as an exotic species in Greece (Salata et al, 2017) and Spain (Reyes & Espadaler, 2005;Reyes-López et al, 2008), while as likely native to North Africa (Wetterer, 2012). In Sicily, it is found in both natural and anthropogenic habitats, and many species appear to be naturally present in both Sicily and North Africa (Alicata & Schifani, 2019). Monomorium subopacum (Smith, F., 1858) was considered as exotic in Greece by Salata et al (2017), while it is usually considered native in the Mediterranean region, however it was removed in a more recent list by the same authors (Salata & Borowiec, 2018).…”