Remarks on the presence of Eristalinus (Eristalodes) taeniops (Wiedemann, 1818) (Diptera, Syrphidae) in Piedmont (Italy) and Canton Ticino (Switzerland). In this paper, the authors confirm the presence of Eristalinus (Eristalodes) taeniops (Wiedemann, 1818) in some areas of south-central Piedmont (western Italy) and in a locality in Canton Ticino (southern Switzerland). The present contribution reports on occasional findings detected primarily in industrial contexts within the wells of the process water discharge, confirming the ability of this species to grow in organic sludge of various nature. Further investigations may detect a more widespread presence of the species in the northwest of Italy.