Abstract: 　Objective To further investigate the life cycle and intermediate host of Thelazia callipaeda in China. Methods Dogs and rabbits were experimentally infected with larvae of T. callipaeda from naturally infected houseflies Musca spp. and fruit flies Amiota okadai. Houseflies and A. okadai bred in laboratory were fed with newborn larvae of T. callipaeda to define the intermediate host of the eye worm. Results Two rabbits and one dog were infected with 34 larvae of T. callipaeda taken from 493 naturally infected A. okadai. As a consequence, 11 adult worms were harvested from the experimentally infected animals 18 to 44 days after infection. The development process of T. callipaeda larvae in A. okadai included three successive stages. The infective larvae migrated through the hemocoel to the head and proboscis of A. okadai. Complete larval development in A. okadai required 14 - 17 days under appropriate temperature. Infective larvae entered the conjunctiva sac of the definitive hosts (dogs, cats, and man) when infected A. okadai sucked their eye secretions. The larvae grew into adults, with two ecdyses in the process of development. The adult females began to produce newborn larvae in 35 days after infection. The longest life-span of T. callipaeda was more than 30 months. Conclusion A. okadai is the intermediate host of T. callipaeda in China.

Key words: Thelazia callipaeda, Amiota okadai, life cycle, intermediate host