In 1989 a fungus killed large numbers of gypsy moths near this site. The gypsy moth,Lymantria dispar, had been introduced into the United States about 1868 near Medford, MA.  Within ten years dramatic defoliation had occurred at several localities, and a governmental effort tried to eliminate the introduced insect pest. The attempts were unsuccessful, and the moth spread westward across the United States destroying whole forests by eating foliage of many plant species but favoring oaks and aspens, which can be completely defoliated. In 1904 an insect pathogenic fungus specific to the gypsy moth, Entomophaga maimaiga, was introduced to North America from Asia in an attempt to control the gypsy moth. The effect of the fungal introduction was not realized until moth epizootics caused by the same fungus were observed in Connecticut, New Hampshire, and Massachusetts in 1989. Since then the fungus has spread and been introduced more widely. A mystery remains: Was the fungus really present and unseen for 85 years since its original introduction or were other introductions after 1904 responsible for the continuing outbreaks of Entomophaga maimaiga. 

Entomophaga maimaiga-infected larvae hang from the tree trunks with their heads pointed downward and their prolegs extended laterally, as hyphal bodies fill their body cavities. The carcasses remain intact until the infectious hyphae and spores break out to be released into the environment. Under favorable weather conditions fungal spores germinate in leaf litter and infect unlucky caterpillars that fall from trees and then attempt to crawl back up the tree.  If conditions are wet enough the fungus produces spores that spread to other caterpillars feeding nearby.  Some of the larger caterpillars become infected as they rest in the ground cover during the day. Infected caterpillars usually die in late July, and new spores are produced to continue the fungal life cycle into the next year. As Entomophaga maimaiga continues to regulate gypsy moth populations over the short term in North America, scientists await long-term effects of Entomophaga maimaiga on gypsy moths. 

--R. M. Camors