GRAND RAPIDS, Mich. — The City of Grand Rapids Forestry division is asking for help from residents in controlling the population of spongy moths (formerly known as “gypsy moths”) to protect the city’s urban tree canopy.
Spongy moths are an invasive species that has been present throughout Michigan for over 40 years. Spongy moth egg masses can contain over 1,000 larvae that hatch into leaf-eating caterpillars.
When the caterpillars significantly defoliate trees, the trees become weaker and vulnerable to fatal diseases.
City Forester Dan Coy says there are ways the community can help prevent this. “We do our best to target and treat the most densely populated areas of spongy moth but rely on community members to help with the rest,” Coy said. “The needed tools are common household items, so most people can get started right away.”
How community members can help control the spongy moth population:
Now through late April, residents can help control spongy moth populations in two ways. Start looking out for egg masses on tree trunks and scraping them into a cup of soapy water using a plastic putty knife or other dull scraping tools. Egg masses are light brown, sponge-like in appearance, and are about the size of a quarter.
Additionally, wrap a double band of duct tape around tree trunks with the sticky side facing out to prevent hatched caterpillars from moving up the tree to the leaves.
For more information on spongy moths, how to identify egg masses, and video tutorials on egg mass scraping and tree wrapping, visit the city’s website here.