Pébrine
Pébrine is a disease of silkworms, which is caused by microsporidian parasites, mainly Nosema bombycis and to a lesser extent Variomorpha, Pleistophora and Thelohania species.
The silkworm larvae infected by pébrine are usually covered in brown dots and are unable to spin silkworm thread. Louis Pasteur was the first one to recognize the cause of this disease when a plague of the disease spread across France.