Gypsy moth in Wisconsin
This website has links to information about gypsy moth identification, locations, pest control and management, aerial spraying and more from the Department of Natural Resources, the University of Wisconsin Extension, and the Department of Agriculture, Trade and Consumer Protection.
What is gypsy moth?
Gypsy moth is an invasive, leaf-eating insect that can feed on most types of trees and shrubs found in North America. When their populations are high, gypsy moth caterpillars can strip an entire neighborhood or forest of leaves during late spring and early summer. Extreme defoliation, especially when repeated over multiple years, puts stress on trees and may lead to mortality the following spring.
Management information for property owners
Management options for your trees
For yard trees and small acreages, we recommend these resources:
For properties of 20 acres or more, we recommend these resources:
DATCP Slow the Spread Program
DATCP conducts aerial sprays to slow the spread of gypsy moth in western Wisconsin. Traps are installed prior to the appearance of adult moths to determine where small, isolated populations may be present. These populations are then targeted using aerial sprays to help slow the pest's spread. To learn more about the program and find treatment updates, visit the DATCP webpage.
During the spring and summer months, aerial spray information is frequently updated on the toll-free gypsy moth information line: 1-800-642-6684. Press 1 to listen to a recording about the latest updates, including treatment locations, timing and completion. You can subscribe to receive email updates about spray plans (scroll to "Plant Industry," click on "Spray Plans").
The map below shows counties (in yellow) where aerial sprays were conducted in 2018. Counties shown in blue participated in the DNR's now-deactivated suppression program. Next year's map will be posted when spray plans are confirmed sometime in February or March. Visit DATCP's interactive spray map or click on the map icon to see where treatments are planned within each county and which products will be used.
Gypsy moth quarantine
Gypsy moth is currently found in the eastern two-thirds of Wisconsin. County-level quarantines are in place to restrict movement of materials that may carry gypsy moth, such as wood products and outdoor household items, from quarantined counties into new, non-infested counties or states. For more information, visit the DATCP quarantine webpage.
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