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Gypsy Moth Survey
Order: Lepidoptera
Family: Lymantriidae
Scientific name: Lymantria dispar (L.)
Common name: gypsy moth (GM)

gypsy moth caught in trap
gypsy moth trapsurvey tech. with gypsy moth in trap
Survey Objectives: To monitor the state for gypsy moth. Each year ODA places approximately 18,000 gypsy moth traps across the state. Placing traps allows ODA to detect any infestations when they are small and more easily eradicated.
Survey Technique: Gypsy moth traps are placed at specific densities across the state. The traps are tent-shaped, made of heavy paper, and are orange-red or lime green in color and are hung in suitable host trees. Adult male gypsy moths are attracted to a female-scented lure inside the trap and get stuck on the sticky inside surface.
Trap Placement: Traps are placed in good hosts such as oaks or other deciduous trees and shrubs. The traps may be placed in front yards (with permission), roadsides, parks, campgrounds, etc. The traps are generally placed in May and removed in September.
Trap Servicing: Traps may be serviced as frequently as every two weeks by an insect survey technician. In some areas traps may be placed and then removed with no checks in between.
Identification of Specimens: The survey technicians collect any suspect moths and immediately send them to the lab in Salem. An entomologist will identify them.
What if Detected: If a gypsy moth is detected it is likely that more traps (25-49 per square mile) will be placed in the area the following spring. If no moths or other life stages are found, then the number of traps will be reduced for the second season. If no moths are found after two years of intensive trapping, then the trap density will drop to detection levels (1-2 per square mile). If many moths are detected in a particular area it is probable that there is a small infestation. The area is searched for other life stages such as egg masses. If other life stages are found then it is likely that the area will be treated the following year in April and May. Details of a current or previous spray program is located on the ODA website.
Survey Results: After the end of each season survey results are published in the Plant Division Annual Report.