Hoverfly (Diptera: Syrphidae) assemblage of an oak–hornbeam in the Merlino Wood Natural Reserve and implications for its conservation

Merlino Wood is a typical oak–hornbeam forest in the Po Plain hydrographic region. It is one of the few remaining lowland forests in Northern Italy and is a Regional Natural Reserve and a Site of Community Interest (code IT1160010). This is the first survey on hoverflies in the study area and they act as bioindicators to assess habitat conservation. Sampling was performed with three Malaise traps and an entomological net. A total of 61 species of Syrphidae were recorded between March and October 2019. Three of the species observed are considered to be under threat in Europe, three species have been recorded for the first time in Piedmont and Heringia latitarsis (Egger, 1865) has been recorded for the first time in Northern Italy. The Syrph the Net analysis has been used to assess habitat conservation. It shows good preservation of xylosaprophagous species, while the conservation conditions of other larval trophic categories are poor.