Gasterophilus pecorum

Gasterophilus pecorum is a species of the genus Gasterophilus that parasitises horses and other equids.
G. pecorum is a significant threat to equids in the desert steppe of Xinjiang, China, where it is the dominant botfly species. In the Kalamaili Nature Reserve, China, G. pecorum is a major problem for the health of Przewalski's horse, which has been reintroduced in the area.
Check out Wikipedia for more details!