The gypsy moth (Lymantria dispar), a native of Asia, Europe and Africa was introduced to the United States in the 1860s for its potential use as a silk producer. Primarily feeders of oaks and other hardwood tree species, larvae and adult moths consume foliage at alarming rates from April through June. Since the 1980s, most of Virginia, including Warren County has been affected by this outbreak pest. Young instars can be easily identified by a dark body with orange spots along their back. Older larvae have pairs of red and blue tubercles on their back.
Popular techniques to estimate the density of gypsy moths are over-wintering egg mass counts and male counts in pheromone traps. Every autumn, the gypsy moth coordinator will perform county-wide egg mass counts, while taking into account egg mass age, size, viability and forest composition.
Gypsy moth populations are best managed with biological or chemical insecticides; additionally, homeowners on small properties can resort to egg mass treatments with oil solutions before egg hatch and tree banding after egg hatch.
For additional information on gypsy moth biology, monitoring and control, please visit the Gypsy Moth in Virginia website and the Gypsy Moth Management for Homeowners on Small Properties publication.
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