Any of various stout, two-winged flies, chiefly of the genera Gasterophilus and Oestrus, having larvae that are parasitic on various animals, especially horses and sheep, and sometimes on humans.

• 马蝇一种胃蝇属和狂蝇属身体大的双翼蝇，其幼虫寄生于多种动物，尤其是马和羊，有时也寄生在人体内