Solenopsis fugax (Latreille 1798)

Schifani, Enrico, Csősz, SÁndor, Viviano, Roberto & Alicata, Antonio, 2021, Ant diversity on the largest Mediterranean islands: on the presence or absence of 28 species in Sicily (Hymenoptera, Formicidae), Natural History Sciences 8 (1), pp. 55-70 : 65

15. Solenopsis fugax (Latreille 1798)

The taxonomy of most Solenopsis species in the Mediterranean is still in dire conditions with a few exceptions. One of the problems regarding all the remaining species has been confusion under the name S. fugax . Similar to L. alienus and L. niger for Lasius s. str. (as mentioned before), the name S. fugax was extensively used to name most Solenopsis populations in the region avoiding serious identification efforts. Such a confusing approach has long been justified by the lack of clarity regarding the concept of S. fugax itself. Since Galkowski et al. (2010) finally provided a clearer definition of S. fugax , it became possible to test whether many populations previously assigned to S. fugax truly represented this species. While S. fugax convincingly appears to be the sole species of its genus in Central Europe, there are many Mediterranean taxa with a similar look, and its distribution in the Mediterranean is still unclear (Seifert, 2018). For instance, a recent examination of newly collected specimens and museum material suggested S. fugax to be absent from Sardinia, where only S. lusitanica Emery 1915 (and S. orbula ) may be present (Schifani et al., 2021b). In Sicily, S. fugax was recorded from several localities by Donisthorpe (1927), Baroni Urbani (1964a), and La Pergola et al. (2008). In addition, it was recorded from the circum-Sicilian island of Ustica (Riggio & De Stefani Perez, 1887), Aeolian (Kutter, 1927), and Egadi islands (Scupola, 2009). We never found S. fugax during our surveys in Sicily and on the Egadi and Aeolian islands (see also Schär et al. 2020; authors’ unpublished data), even at higher altitudes where Central-European species are more common. Instead, the widespread form that we encountered is provisionally named S. latro sicula (Schär et al., 2020) . The attribution of the Sardinian population to S. lusitanica awaits to be confirmed by a proper revision (Schifani et al., 2021b), as well as the identification of the Sicilian one as S. latro sicula . In addition, a review of North African Solenopsis taxonomy, regrettably plagued by scientific names based on few workers, is strongly needed to understand whether Sicilian Solenopsis are related to them. At the same time, our finding undermines the assumption that S. fugax is widespread in Italy, where the only reliable records come from the northern regions (Castracani et al., 2020; Schifani et al., 2021b). The recognition of S. latro sicula from S. fugax may be based on worker chaetotaxy (see images in Schär et al., 2020), but, similarly to Sardinian S. lusitanica , gynes and males have better diagnostic features, especially size, head shape, and sculpture (Galkowski et al., 2010; Fig. 5 ).

Figures

Fig. 5 - Solenopsis latro sicula. a-b,e) Queen / regina; c-d,f) male / maschio. Monte Pellegrino. Scale bar / scala grafica: 0.5 mm (ESC).