Michigan! If You See This, Grab a Bucket of Soapy Water!
Pure Michigan, the land of breathtaking natural beauty, stunning forests, and the invasive species that continues its effort to destroy our beautiful canopy. Meet the spongy moth larva.
A New Name Doesn't Change the Impact It Has On Michigan Trees
Do those little hairy, webby egg sacs look familiar? They should, the spongy moth has been on Michigan's Invasive Species naughty list since the 1990s:
The last large-scale spongy moth outbreak occurred in Michigan from about 1992 to 1996. Since then, localized areas have experienced occasional outbreaks. Suppression efforts in the 1990s have continued to keep spongy moth populations largely in check while naturalizing infestations into Michigan’s forests and urban forest ecosystems.
Sounds familiar right? That's because prior to March of 2022, you knew this little fuzzy flier as a 'gypsy moth'. The name was changed due to concerns the original name can be used as a slur.
Imagine you're walking on your favorite trail, one you walk at least once a week, and you notice that some of the trees you come across are looking a little sparse. It seems they have been stripped of their greenery down to their skeleton-like branches. Who's the culprit? The spongy moth LARVA. Adult spongy moths only care about reproducing, so they are too distracted to really cause any damage. It's the product of that reproduction that causes significant damage to our Mitten State trees.
Where Should I Look for Larva?
According to the Invasive Species Centre, these little larvae aren't too picky about which tree they call home:
A caterpillar feeds primarily on hardwood trees, and may feed on softwood trees.
Some favoured host tree species include:
- Oak (Quercus spp.)
- Maple (Acer spp.)
- Birch (Betula)
- Alder (Alanus spp.)
- Hawthorne (Crataegus spp.)
See Spongy Moths? Take Action
Michigan.gov recommends the following when you encounter the spongy moth at any stage of development:
- Before hatch, inspect decks, outdoor furniture, fences, and trees, focusing on your favorite outdoor use areas. Scrape any accessible egg masses into a bucket of soapy water or burn or bury them.
- After hatch, use a whisk broom to sweep young caterpillars into a bucket of soapy water. Let them soak overnight, then dispose.
- Make a tree trunk trap: Cut a band of burlap 18 inches wide and long enough to go around the tree trunk and overlap a bit. Tie a string around the center of the band to make a two-layered skirt around the trunk. When caterpillars climb trees daily to feed, they will get caught in the band. Scrape them into a bucket of soapy water to kill them.