The enigmatic case of Lipoptena sp. in the Bosco della Mesola Nature Reserve (Italy).

Species belonging to the genus Lipoptena have received limited attention and have historically been subject to misidentifications. Recent records of L. fortisetosa in Europe have rekindled interest in these hippoboscids, leading to the discovery of a new species in Spain in 2024, which has been named L. andaluciensis. During an opportunistic sampling conducted in March 2023 and October 2024 on the Italian red deer (Cervus elaphus italicus), an Italian endemic subspecies, within the ancient relict lowland forest of the Bosco della Mesola Nature Reserve, hippoboscids morphologically identical to L. andaluciensis were collected and examined. This represents the first record of this species in Italy. In total, 257 specimens of Lipoptena were collected and analysed (161 in 2023 and 94 in 2024), all identified as L. andaluciensis. Additionally, Lipoptena specimens collected from fallow deer in 2007 within the same nature reserve, which had remained unidentified until now, were re-examined. A total of 66 specimens were reassessed, of which 63 were morphologically identified as L. andaluciensis and 3 as L. cervi. Morphological identification of the 2023 and 2024 specimens was further confirmed through molecular analysis using COI as a barcode marker. Molecular analysis also revealed the presence of a nuclear copy of the COI gene (NUMTs) in the nuclear genome of L. andaluciensis. The discovery of L. andaluciensis in Spain and in Italy since 2007 raises the possibility that this species has a much broader distribution, particularly at lower altitudes and within a Mediterranean climatic zone. It is plausible that its presence has so far gone unnoticed or has been misidentified.