Entomophaga maimaigaHumber, Shimazu&Soper was recovered from gypsy moth,Lymantria dispar(L.), populations from Massachusetts, Connecticut, New Hampshire, Vermont, eastern New York, northeastern Pennsylvania, and New Jersey in 1989 and 1990. NoE. maimaigawas recovered from cadavers of gypsy moth larvae collected in western New York, western Pennsylvania, West Virginia, or Virginia in either year despite high levels of rainfall in these regions in May of both years. In 1990,E. maimaigawas recovered in many areas that bordered the 1989 distribution (Maine, central Pennsylvania, central New York, Delaware, and northeastern Maryland) where it had not been recovered in 1989, possibly due to spread of the disease. In 1989, mortality of gypsy moth larvae from sites in Massachusetts was correlated with rainfall, but not with population density.