March

Spray or scrape egg masses and watch for treatment program

Gypsy moth eggs are tough! They can survive temperatures as low as –20°F.

You can continue to spray egg masses with Golden Pest Spray Oil when the temperature is over 40°F. The oil kills the eggs, reducing the population of gypsy moth next spring.  This spray oil is available to purchase online or at some garden centers and retailers.  If you have many egg masses, consider adding food coloring to your spray oil so you can see which egg masses you’ve already treated.  Although more difficult, and you must be careful not to damage the bark of the tree, you can also scrape egg masses into a cup and either microwave then on high for 2 minutes or cover them with soapy water for 2 days.  You may then discard eggs in the trash. Don’t leave any part of the egg mass attached and don’t allow it to fall onto the ground, they will survive to hatch next spring!

Treatment areas planned for the state’s Gypsy Moth Suppression Program are posted online in March at: www.gypsymoth.wi.gov.  The yellow and blue Wisconsin map on that webpage shows which counties will be sprayed by the Department of Agriculture, Trade and Consumer Protection and by the Department of Natural Resources.  Treatments start each year in May.

Spraying gypsy moth egg masses with an approved horticultural oil

Photo Credits: Bill McNee WI DNR.