In some years, depending on the Gypsy Moth caterpillar population, the PA DCNR Bureau of Forestry conducts an Integrated Pest Management Program that includes a Spray Suppression Program in early Spring.
High populations of gypsy moth caterpillars defoliate trees and leave them open to other disease and potential tree mortality.
Homeowners should notice in July and August caterpillars going into the pupal stage and then become moths. The female moth has white wings, but does not fly: she lays eggs that will overwinter until April of the following year. The male moth has brown speckled wings and flies in an erratic pattern.
The County Vector Control Office conducts survey assessments of the moth egg masses to determine the following years need for spraying.
Resident requests for survey are taken until August, based on DCNR Bureau of Forestry criteria:
Average 500 egg masses/acre
Minimum 50 acres
Contact 717-240-6539 for a question regarding the surveys.
Although large quantities of caterpillars may have been active earlier in May, they quite often are killed by virus and fungus and therefore not always an accurate gauge of a following year infestation.
Residents are advised that should they find gypsy moth caterpillars or egg masses on their trees, they may want to consider a control method at the DCNR Homeowner Link.
It would be misleading for the homeowner to believe that because they are included in a spray area that their gypsy moth caterpillar associated problems will cease completely after spraying. Where very high caterpillars exist, the spray material may not be as effective and homeowners may continue to have some nuisance caterpillars and defoliation.