Efforts To Control The Spongy Moth In Southeast Minnesota

This invasive pest that's been causing problems in Minnesota for over 50 years-- and its new, less offensive name-- is now being targeted here in Rochester.

According to the Minnesota Department of Natural Resources (DNR), invasive species are those species that are not native to Minnesota, but once they're here, can cause real economic, social, or environmental harm, or harm to human health. They can be found both in the water and on land here in the North Star State.

Common Invasive Species Threatening Minnesota's Ecosystem

The DNR says Minnesota's natural resources are threatened by a number of invasive species, like zebra mussels, Eurasian watermilfoil, common buckthorn, and emerald ash borer. And now we can add what we used to call the 'gypsy moth' to the list.

Actually, the moth formerly known as 'gypsy moth' is an invasive species here in Minnesota that the Department of Natural Resources (DNR) has been trying to control since the early 70s. And there's a good reason.

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The DNR says it feeds on more than 300 species of deciduous trees and shrubs, including aspen, oak, and birch. Those moths eat the leaves on suspect trees, which then leaves them vulnerable to disease-- and can even kill them.

Why the Gypsy Moth is Now Called the Spongy Moth

A few years ago, the DNR noted it was following the lead of the Entomological Society of America (ESA) and was discontinuing the use of the term 'gypsy moth' when referring to Lymantria dispar (that's the moth's Latin name) and would instead be using the name 'spongy moth.'

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So was it being replaced? The ESA said it's because the term 'gypsy moth' contains a derogatory term for the Romani people of northern India. So now, in the latest Common Names of Insects and Related Organisms List, the ESA said that the new name for Lymantria dispar will be 'spongy moth.'

The ESA said the new name (which refers to the sponge-like egg masses the moth produces) was chosen from more than 200 nominations evaluated by a group of more than 50 scientists.

Aerial Spongy Moth Treatments Scheduled for Rochester and Olmsted County

Now, the Minnesota Department of Agriculture (MDA) is partnering with Olmsted County and other municipalities to try to curtail the spread of the spongy moth in southeast Minnesota. Their plan will apply a chemical pheromone by airplane over several areas in our neck of the woods this spring and summer.

According to Olmsted County, the following areas would be impacted: Carly State Park near Plainview, portions of Stewartville, as well as portions of northeast, north, and southeast Rochester. There are open houses scheduled on March 31st, 2026, and April 1st, 2026, where you can learn more.

So, whether you call it a 'gypsy moth' or 'spongy moth,' you can get more info here. And, speaking of names, check out this list of the naughtiest-sounding names in Minnesota!