During the 1974 growing season, larvae of the alfalfa weevil, Hypera postica (Gyllenhal), were examined for pathogens. Three larvae out of 715 examined were infected with a microsporidium. This infection was present in both Washington and Mason counties in Illinois.
Roberts, S. J.; Maddox, J. V.; Bartell, D. P.; and Armbrust, E. J.
"Disease as a Larval Mortality Factor in Alfalfa Weevil, Hypera Postica (Coleoptera: Curculionidae) Populations in Illinois,"
The Great Lakes Entomologist, vol 10
Available at: https://scholar.valpo.edu/tgle/vol10/iss4/5