[Musca osiris--a new intermediate host of Thelazia gulosa]

Musca osiris Wd. was first recorded as an intermediate host of the nematode Th. gulosa. In Tadjikistan Musca autumnalis Deg. was first recorded as an intermediate host of Th. gulosa and Th. skrjabini. The flies are suggested to be used as indicators of thelaziasis infection by using a key suggested for the first time for the definition of species of larvae belonging to the genus Thelazia during differentiation of infected larvae from flies.