Epidemiology of MdSGHV in Musca domestica

Musca domestica salivary gland hypertrophy virus (MdSGHV) is a disease that enlarges the salivary glands of Musca domestica (the common house fly), as well as causes infertility in female house flies. An infected female fly will no longer produce or lay eggs and will refuse a male’s mating attempts. Collaborating with the University of Florida’s Entomology and Nematology Department, we have hypothesized that the virus is primarily transmitted through male-male interactions. The constant interaction between males causes damage to the flies’ cuticle. When the virus is present on the cuticle, this damage allows the virus entry into the hemocoel, which subsequently infects the internal organs and in particular the salivary glands. The virus adheres to the fly cuticle at contaminated resting sites and contaminated feeding sites. Infection per os is another possible mode of transmission but insu cient to sustain the virus in the fly population. For females, MdSGHV seems to be transmitted largely per os with random occurrences of cuticular damage that take place at the contaminated food and resting sites. There is no evidence that females exhibit aggressive behavior, or that mating causes cuticular damage. Vertical transmission does not seem to be a mode of transmission. We developed a system of di↵erential equations to model the transmission of MdSGHV for a population of Musca domestica at Florida dairy farms. The model is based on the above understanding of the transmission of the virus together with some other simplifying