Catoctin Mountain Park Announces Spraying of Btk for Control of Gypsy Moths Catoctin Mountain Park is administering a gypsy moth spray program with the assistance and cooperation of the U.S. Forest Service. Gypsy moth egg mass surveys, completed in 2000, indicate that gypsy moth populations are sufficient to cause significant tree defoliation in a portion of Catoctin Mountain Park. Approximately 800 acres of the park have egg mass densities above the U.S. Forest Service threshold for treatment.
Treatment is recommended when defoliation is likely.
Btk has been chosen for spraying because it is a biological rather than a chemical insecticide and due to its limited toxicity which affects only caterpillars. Spraying dates will coincide with the proper point in the gypsy moth life cycle and favorable weather conditions. Flexibility of the spraying dates assures a greater success in controlling gypsy moth populations. Trails will be marked with informational signs and spray maps will be available at the Visitor Center while the Btk is being applied. Catoctin Mountain Park is one of 384 units administered by the National Park Service, U.S. Department of the Interior.