House fly is a major problem world wide. It vectors pathogens of humans, food products, and domestic animals. A newly discovered virus attacks the salivary glands of adult flies of both sexes. The pathology of the virus is that it prevents females from producing eggs and prevents mating in both sexes. Internally it causes hypertrophy or enlargement of the salivary glands. In order to produce the numerous virions essential for transmission, a considerable amount of energy in the form of food intake must be essential.