Microsporidian pathogens of the gypsy moth: research update.

Three genera of microsporidia, Vairimorpha, Nosema and Endoreticulatus, infect gypsy moth larval populations in Europe and have been documented to reduce the intensity and duration of outbreaks. Manipulation of these chronic pathogens involves knowledge of taxonomic relationships, host specificity, virulence, transmission, strain variability, interspecific competition and other aspects of host-pathogen interactions. Our ongoing research has addressed these issues and continues as we now conduct inoculative introductions in the U.S. and augmentative releases in Eastern Europe.