Oscinian \Os*cin"i*an\, n. (Zool.) Any one of numerous species of dipterous flies of the family {Oscinidae}. [1913 Webster] Note: Some, whose larvae live in the stalks, are very destructive to barley, wheat, and rye; others, as the barley fly ({Oscinis frit}), destroy the heads of grain. [1913 Webster]