Syrphus fly \Syr"phus fly`\ [NL. Syrphus, the generic name, fr. Gr. ?, ?, a kind of winged insect.] (Zo["o]l.) Any one of numerous species of dipterous flies of the genus {Syrphus} and allied genera. They are usually bright-colored, with yellow bands, and hover around plants. The larv[ae] feed upon plant lice, and are, therefore, very beneficial to agriculture.