- Contact information
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- Bill Cosh
Director of Communications
Gypsy moth media kit
The best resource for information on this topic is Wisconsin Gypsy Moth.
Gypsy moth is Native to Europe and Asia. Gypsy moth caterpillars feed on the leaves of up to 500 species of trees and shrubs, favoring oak. Heavy defoliation threatens the trees' health by causing stress and making them more susceptible to damage by other pests, diseases, and extreme weather conditions.
At the request of landowners and communities, the DNR's Gypsy Moth Suppression Program works with county governments to conduct aerial sprays to reduce high gypsy moth populations so that they do not cause heavy tree defoliation. The Suppression Program works in areas where gypsy moth is well established.
The Department of Agriculture's Slow the Spread Program works to slow the spread of gypsy moth into new areas. They spray and set traps where the pest's population is low or just starting to build. In Wisconsin, this is generally the western half of the state.
Airplanes are the most efficient and cost-effective way to apply products to the tree canopy over a large area. Aerial application uses less pesticide per acre and is less expensive per acre than ground-based pesticide applications. Professional spray plane pilots are licensed and certified by the Federal Aviation Administration. The planes fly low and loud over spray areas. Spraying may begin at dawn and is weather dependent.
Btk is a strain of common soil bacterium found naturally. The formulation used in the Suppression Program has been listed with the Organic Materials Review Institute as safe for use in organic food production. Btk only affects certain caterpillar species, and only when they eat it. Btk breaks down in sunlight within 10 days, is sticky, and is not known to be harmful to humans, pets, wild animals, birds, honeybees, or fish. You may wish to stay indoors and keep your windows closed during a nearby spray if you have severe food allergies or chemical sensitivities.
Gypchek is the brand name for Gypsy moth nucleopolyhedrosis virus (NPV). This virus infects only gypsy moth caterpillars and naturally occurs wherever gypsy moth is present. The Suppression Program sprays it on the leaves instead of Btk where endangered species such as Karner blue butterfly exist.
What you can do
Aerial spraying is only one step in managing gypsy moth populations and will not eradicate this pest. When gypsy moth populations are reduced enough to protect trees from heavy defoliation they still may be more numerous than is tolerable or comfortable to property owners. A combination of efforts is critical to effectively manage this pest. Homeowners are encouraged to use several strategies including physical controls, ground based sprays where populations are extremely high, and spreading the word to neighbors. Do NOT rely on aerial spraying alone. Also, do your best to prevent moving gypsy moth around and into new areas. Keep firewood local and inspect your outdoor items and vehicles for gypsy moth hitch-hikers before traveling.
Maps of all of the spray areas (called "spray blocks") are available to download from gypsymoth.wi.gov. Click on the county you are interested in on the blue and yellow Wisconsin map on that webpage. The maps are available as pdf documents and show the areas to be treated as well as what the treatment will be.
Blue counties will be treated by the DNR Suppression Program. Yellow counties will be treated by DATCP's Slow The Spread Program.
Anyone unable to access the internet who would like spray maps mailed to them can request specific maps by calling a staff member through the Gypsy Moth Information Line at 1-800-642-6684 and making the request. Choose menu option # 2 for DNR staff 7 a.m. - 10 p.m., 7 days per week. Choose menu option # 3 for DATCP staff during business hours or leave a message.
Correct timing for aerial spraying for gypsy moth depends on a combination of:
- seasonal weather patterns;
- daily weather conditions;
- gypsy moth caterpillar development; and
- tree leaf development and size.
Because of all of these factors it is impossible for us to know for certain when we will be spraying a particular area until spray time arrives. However, we do watch forecasts closely and make plans at least one day ahead based on weather predictions, gypsy moth caterpillar and leaf observations.
Staying up to date
You can stay updated daily on upcoming spray plans and the locations where spraying has been completed.
Call the Gypsy Moth Information Line at 1-800-642-6684, option # 1: A recorded message is updated daily during spray season.
Subscribe to the DNR Gypsy Moth Email Notification List. Emails are sent daily during spray season and approximately once every three months during the rest of the year to offer tips on seasonal management of gypsy moth populations for home owners. You may unsubscribe at any time.
A yellow Ag Tractor plane will be used by the DNR Suppression and DATCP Slow the Spread Programs to treat for gypsy moth.
If you are in or near a spray block, be expecting low-flying, loud planes perhaps as early as dawn on spray days in your area. Stay updated on spray activities so you know when to expect to see and hear the planes.
- Gyspy moth spray activities begin as early as dawn and continue throughout the day as weather permits.
- Planes fly low over the spray areas and may be only 100 feet above the ground.
- All 2013 spray blocks will be sprayed by bright yellow planes similar to those used for crop dusting in agricultural fields.
- Planes will fly over non-treatment areas as they travel between spray blocks. Planes flying over non-treatment areas will NOT spray them.
The Suppression Program faces an enormous challenge of alerting residents about spray activities on an uncertain schedule. A minimum set of measures is taken.
- The Gypsy Moth Information Line at 1-800-642-6684 is updated daily with a recorded spray schedule message (menu option # 1) and is staffed to answer questions (menu option # 2 for DNR and menu option # 3 for DATCP).
- The DNR runs an Email Notification List to update subscribers daily on spray schedules during spray season and about once every three months during the rest of the year with tips on managing gypsy moth populations for homeowners.
- Counties provide a list of all hospitals, clinics, nursing homes, day cares, schools, churches, cemeteries, airports, helipads, sheriff and police departments, 911 dispatches, and more in or near the spray areas. Specific staff members at these locations are contacted with the information about areas to be sprayed, what will be sprayed and the options for staying updated via the Gypsy Moth Information Line and Email Notification List.
- An additional mailing is sent to schools in or near spray areas. This mailing includes the same information in a format that the school can make available for students to take home to their parents or include in their newsletters.
- Counties and municipalities are required to hold public meetings in January or February to alert residents of the proposed spray activities.
- Counties and municipalities in the Suppression program may send notice to all property owners within spray treatment areas in January or February.
Wisconsin Gypsy Moth is an excellent resource for general information, spray program information, tips and strategies for controlling gypsy moth populations and much more.
Gypsy Moth Information Line 1-800-642-6684
The Gypsy Moth Information Line provides a variety of menu options.
- Menu option # 1
- A recording of updated spray plans and completed spray activities
- Menu option #2
- DNR staff knowledgable about gypsy moth and the DNR Suppression Program
7 days per week from 7 a.m. - 10 p.m.
- Menu option #3
- DATCP staff knowledgeable about gypsy moth and DATCP Slow the Spread Program during business hours or leave a voice mail message
- DNR Gypsy Moth - please allow a few days for a reply
- Colleen Robinson Klug
DNR suppression program public information officer
- Donna Gilson
DATCP public information officer
Gypsy moth aerial spraying to start soon
Issued by DNR Central Office on Tuesday, May 14, 2013 at 2:09:22 PM
Watch out for gypsy moth – and act soon
Issued by DNR Central Office on Tuesday, April 16, 2013 at 12:48:14 PM
Public invited to learn about Gypsy Moth treatment plans for Governor Dodge State Park in 2013
Issued by DNR South Central Region on Thursday, January 24, 2013 at 9:00:07 AM
Three Counties Added to Wisconsin Gypsy Moth Quarantine
Issued by DATCP on March 20, 2012