Gypsy Moth Defoliation in Virginia - 2003

Click here to see a larger version of the map.This year was hard on the gypsy moth, which is good. Hatch was poor in some places and slow almost everywhere. Cool, wet weather and a late freeze kept many hatchlings from getting a good start and fungus disease spread rapidly among developing caterpillars. A large percentage of larvae failed to reach the final stage. Despite this, populations were dense enough in some regions to cause nearly 80,000 acres of defoliation that could be mapped from the air, 70% of which occurred in Alleghany, Bath and Highland Counties.

Mapping was particularly difficult because there was so little suitable weather for flying, and a sketchmapper was not always available. In addition, most defoliation was incomplete because larvae died before consuming all the foliage. The effects of other defoliators, oak anthracnose, hail and freeze injury all contributed to confusion over what had been caused by the gypsy moth.

Slow-The-Spread applications next spring to disrupt mating in low-density populations will include 16 blocks covering 118,401 acres in Bland, Carroll, Floyd, Franklin, Giles, Montgomery, Patrick, Pittsylvania, Pulaski, and Wythe Counties.