A spongy moth larva eats a leaf.
By Paul Cigan, DNR plant pest and disease specialist
Paul.Cigan@wisconsin.gov or 715-416-4920
In early April, Douglas County became the 53rd Wisconsin county added to the state’s spongy moth quarantine list after a discovery that the invasive insect (formerly known as gypsy moth) had become established in the county.
The United States Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS) and the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) made the determination based on results of a monitoring program of adult moths and other life stages.
A map of Wisconsin counties facing quarantine due to spongy moth. Graphic: Wisconsin DATCP.
While spongy moth males have been trapped in all 72 Wisconsin counties, the invasive pest is considered established only in the 53 counties that are quarantined, all in the eastern three-quarters of the state.
Spongy moth first became established in Wisconsin in the early 1990s and has moved slowly across the state over the last 30 years. Precautions to keep the westward spread of spongy moth to a minimum have included:
- Actions taken by the wood and nursery industries as part of the quarantine.
- Campers and others limiting the distance they move firewood.
- Treatments to manage outlying populations done by the DATCP Slow the Spread (STS) program.
The quarantine regulates the movement of items from areas that are quarantined (shown in red on the map) to non-quarantined areas (white), and to areas outside the state where the pest is not yet established. Regulated items include logs, nursery stock, firewood, Christmas trees and outdoor household goods. For more information on the quarantine for businesses and the general public, visit DATCP’s webpage on spongy moth quarantine and regulations.
The quarantine’s greatest impact will be felt by plant nurseries, Christmas tree growers and wood-using mills because of movement precautions and inspection requirements. Logs, wood products and nursery stock must be certified free of spongy moth before they can be transported into non-quarantined counties or states. DATCP staff will work with businesses to help them achieve the requirements of the quarantine at minimal cost.
Firewood can harbor spongy moth caterpillars, pupae or egg masses. As a result, firewood should not be moved from quarantined counties or states into non-quarantined areas. Users are encouraged to plan ahead and obtain firewood at their destination. All Wisconsin state campgrounds have firewood for sale at or near the campground. Go to the webpage for the state campground you will be visiting to see where and when firewood is available for sale at that property. Individuals also can use the Firewood Scout website to find nearby sources of firewood at or off state properties.
If you have questions, visit the Wisconsin Spongy Moth Portal. Forestry staff may direct questions about the quarantine decision process and implementation to DATCP.