Gypsy Moth In North America

Species in the zygomycetes order are mostly insect pathogens. The entomophthoralean fungus, Entomophaga maimaiga is a widespread gypsy moth pathogen in Asia and epizootics (massive reproduction of the pathogen causing widespread disease in its host) are frequent in Japan.

In 1904 efforts were made to indtroduce this pathogen to control gypsy moth populations in North America. Following its release near Boston, MA in 1910-1911, no infected larvae were recovered and workers concluded that the introduction was a failure.

In 1989 E. maimaiga was discovered to be causing estensive epizootics in several New England States. By 1992 this fungus was recovered through out the range of the gypsy moth in N. America. Since then numerous epizootics have been observed and scientists are attempting to determine how E. maimaiga will effect the long-term dynamics of the gypsy moth in N. America.

Numerous constrains limit the use of entomopathogenic fungi for use as mycoinecticides (pest control). Most of these problems relate to the production and application of material.

Cadaver of a late instar gypsy moth killed by NPV. Note the moist appearance of this older cadaver and inverted the "V" position. Photo by D. Specker

Fungal hyphal bodies and immature resting spores within a recentaly killed gypsy moth larva.

Cadaver of a gypsy moth larva producing abundant conidia, some of which remained attached to larval hairs.

Overwintering resting spores (azygospores) of Entomophaga maimaiga.

Protoplasts of Entomophaga maimaiga that occur within the hemolymph of infected insects.

Conidia of Entomophaga maimaiga actively ejected from cadavers to cause infection during the same season.