New observations on rare and threatened saproxylic hoverflies in North-Western Italy with ecological notes

Background The knowledge on the distribution of saproxylic hoverflies in the Piedmont region has always been incomplete, despite the large wooded areas present in the territory. We know of a few scattered specimens collected in the 19th century, often with a generic or incomplete locality on the label such as “surrounding Turin” or “Alps”. The recent publication of the first European Red List on hoverflies highlights some threatened species including some saproxylics. To fill this knowledge gap we report here unpublished data and establish new ecological note on threatened or nationally scarce saproxylic species actually present in the region. New information In this study, we present new findings concerning rare saproxylic hoverflies. These include the rediscovery of Hammrschmidtia ferruginea (Fallen), 1817, marking its first recorded occurrence in the Italian fauna since the middle of 19th century. Additionally, we report novel observations of the “Chimera fly" Doros destillatorius Mik, 1885, along with further observations on endangered or vulnerable species such as Callicera spp. and Brachypalpus chrysites Egger 1859. Moreover, we document the rediscovery of Criorhina pachymera Egger, 1858, within the Piedmont region, and the first record of Brachyopa grunewaldensis Kassebeer, 2000, within Italy. Comprehensive data detailing these observations are provided herein.