DNR encourages property owners to check for spongy moth egg masses | News

MADISON (WKOW) — The Wisconsin Department of Natural Resources is encouraging property owners to check trees for spongy moth egg masses and plan if treatment is needed.

Spongy moths — formerly known as gypsy moths — are an invasive species in Wisconsin capable of killing trees by eating all of the leaves. They’re “generally established” in most of Wisconsin, and the DNR expects that an outbreak is likely to continue and spread.

The DNR says property owners with the following types of trees should be particularly watchful, although spongy moths can feed on many other plants:

• Oak
• Birch
• Crabapple
• Aspen
• Willow
• Linden (Basswood)

Spongy moth egg clusters can be identified by searching for tan lumps on trees about the size of a nickel or quarter. They can be on trees, buildings, outdoor objects like wood sheds and inside protected places like birdhouses.

Egg masses that are firm or darker in color were made in 2022, while older egg masses feel spongy, are darker in color and do not contain viable eggs.

Treatments for spongy moths include foliage sprays and trunk injections, but physical controls in areas with fewer egg masses are possible as well. For example, egg mass oil can be applied to prevent them from hatching.

If you need to treat your property with an insecticide, search for a professional through the Wisconsin Arborist Associationthe International Society of Arboriculture or a phone book.

Find additional information on the spongy moth onlineincluding egg mass oiling and removal, physical controls, and insecticide application.