Environmental Assessment [for] 1995 Gypsy Moth Suppression Project Fredericksburg & Spotsylvania National Military Park

Alberts, Susan

The gypsy moth was introduced into Massachusetts in 1869, and since that time the spread of this exotic species has been steadily moving southward and westward. The gypsy moth has been found in localized infestations throughout the United States, with populations concentrated in the northeast. The advancing front of the moth, now in central Virginia and eastern West Virginia, is progressing southward at a rate of approximately ten miles per year. Because this pest is often carried by wind or vehicles into non-infested areas any location with suitable habitat is subject to defoliation. A high degree of vehicular visitation coupled with abundant habitat puts Fredericksburg and Spotsylvania National Military Park at a high risk for further defoliation. The National Park Service (NPS) in conjunction with the U.S. Forest Service (USFS) and the Animal and Plant Health Inspection Service (APHIS) began a monitoring program in the park during 1982. Populations remained relatively low and egg mass surveys did not result in any positive finds until 1987, however by 1990 infestations exceeding 20,000 egg masses per acre were found at Ellwood in Wilderness Battlefield. The first year the park experienced extreme defoliation was 1993. To discourage defoliation caused by high gypsy moth populations the park, in response to National Park Service policy and in cooperation with the U. S. Forest Service, has undertaken an integrated pest management program for the gypsy moth. This program emphasizes population monitoring to identify critical action thresholds, for which appropriate management activities can be made most effective. Natural controls are to be maximized with environmentally acceptable insecticides being used only when appropriate. Control efforts proposed for 1994 include one aerial application of biological controls to 217 acres of the 8,000 acres in the park ownership. Six areas within three park units have been defined within the park where populations of the gypsy moth indicate probable defoliation. Five of these areas will be treated, the sixth area is known as Jackson's Flank. Jackson's Flank is located off of Route 3 between the Wilderness and Chancellorsville units of the park and will not be treated because of its isolated location and lack of susceptable resource values. Tree mortality in this area would not be a threat to park structures or visitors, nor would it severely impact any historic resources. The boundaries of the areas to be treated are delineated on the attached outline map (Appendix A). At the present time the primary need for the proposed project is to reduce the impact of the gypsy moth in park development zones. Developed zones include Visitor Centers and grounds, picnic areas, interpretive waysides, and areas of concentrated visitor use. Defoliation of the forest canopy would result in increased mortality in these trees, predominantly oaks, already subjected to recreation related stress. Increased mortality would increase hazards to public safety.