Gypsy Moth Defoliation in Virginia: 2001

Aerial sketchmapping surveys in late June and early July documented 440,409 acres of moderate to heavy, large-area defoliation by gypsy moth caterpillars in Virginia. This figure does not include small, isolated patches of defoliation or extensive areas of light defoliation that are difficult to delineate.

Composite and individual county defoliation maps are located at the bottom of this page.

Defoliation increased greatly from last year’s 70,969 acres, despite widespread virus and fungus diseases that killed large numbers of nearly full-grown caterpillars. It will be particularly important to conduct careful egg mass surveys this fall to assess the potential for defoliation next spring. Gypsy moth populations in some areas collapsed from disease, but in others there are plenty of egg masses to pose a threat for next year.

In addition to severe defoliation in the mountain counties, from Bedford and Roanoke Counties north, there was a dramatic increase in gypsy moth activity across the Commonwealth to the east. In addition to nearly all counties north of the James River, defoliated yard trees and nuisance levels of caterpillars were reported from the following Piedmont and Coastal Plain Counties south of the James: Amelia, Appomattox, Brunswick, Buckingham, Campbell, Charlotte, Chesterfield, Cumberland, Dinwiddie, Isle of Wight, Nottoway, Prince Edward, Prince George, Surry and Sussex. There were even a few acres of defoliation far to the south in Wythe County.

This large-scale increase in population density raises the possibility of a major outbreak, involving the northern half of the Commonwealth. Much depends on the weather and the prevalence of larval disease.

Counties wanting to participate in the Cooperative Suppression Program, which is coordinated by the Virginia Department of Agriculture and Consumer Services (VDACS) and supported in part by the US Forest Service, should identify a gypsy moth coordinator and contact VDACS right away. County gypsy moth coordinators provide public education programs, conduct egg mass surveys, submit proposals for aerial suppression and cooperate with VDACS during spray operations.

Gypsy Moth Damage maps:

All affected counties l Alleghany l Augusta l Bath l Bedford l Botetourt l Clarke l Fauquier l Fredrick l Highland l Loudoun l Page l Prince William l Rockbridge l Rockingham l Shenandoah l Warren l Wythe