Three Gypsy moth surveys conducted by the Ohio Department of Agriculture revealed a slight increase in population densities on State and private forested areas throughout Ohio in 2005. During July of 2005, defoliation was estimated at 5,000 acres in Ohio. This defoliation resulted in several eradication and suppression treatments. Since 1990, the Ohio Department of Agriculture has been conducting gypsy moth suppression projects in the generally infested areas of the State, combined with pheromone trapping and eradication projects in areas not considered generally infested.
The purpose of these projects is to maintain gypsy moth populations below damaging levels in infested areas of Ohio, while identifying and slowing the spread of gypsy moth areas by eliminating isolated gypsy moth populations in the State's uninfested areas. The projects have included many different tactics including insecticides, biological controls, and mass trapping. In 2005, approximately 20,000 acres were treated as part of Ohio's Slow the Spread effort.
In May, 2005, about 2,266 acres were treated in Ottawa county (South Bass Island) to suppress gypsy moth populations and reduce damage to tree foliage. The month of May was also very wet, which enabled the fungal pathogen Entomophaga maimaiga to further reduce gypsy moth populations in some areas of Ohio.
Due to increasing gypsy moth populations in northeastern Ohio, the State and Federal Departments of Agriculture established a quarantine in 1987 to limit the spread of this destructive pest. Gypsy moth populations first reached defoliating levels in 1990. Defoliation peaked in 1995 at nearly 35,000 acres. Increased gypsy moth damage is expected as the insect spreads into the State's unglaciated oak-hickory forestlands.
There is good news to report in the fight against the gypsy moth. A new weapon has emerged. A fungus, Entomophaga maimaiga (Em), has emerged as a tool that can be used against this voracious feeder. This highly virulent and host-specific fungal pathogen of gypsy moth larvae, is known as one of the most important causes of mortality in Japanese gypsy moth populations.
The fungus was probably imported from Japan to areas near Boston, Massachusetts around 1910. This attempt to establish the fungus seemed to fail since extensive surveys did not reveal the pathogen. Em was not observed in North America until June, 1989 when dead caterpillars found clinging to trees in the northeastern U.S. revealed its presence. Ohio first documented the fungus in Trumbull county in 1993.
Read an article Entomophaga: A New Tool in Gypsy Moth Management written by Dan Balser of the Division of Forestry and Allen Baumgard of the Ohio Department of Agriculture that describes the use of this fungal pathogen in fighting the gypsy moth. If you have gypsy moth on your property, call ODA before September 1 at 1-800-282-1955.
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