The web Browser you are currently using is unsupported, and some features of this site may not work as intended. Please update to a modern browser such as Chrome, Firefox or Edge to experience all features Michigan.gov has to offer.
New name for a familiar pest: Gypsy Moth is now spongy moth
March 02, 2022
March 2, 2022
The Entomological Society of America today announced a new common name for the Lymantria dispar moth. The invasive moth most familiar in its voracious, leaf-eating caterpillar stage will now be known as "spongy moth."
Formerly referred to as "gypsy moth," the hairy, yellow-faced caterpillar with pairs of red and blue spots down its back was big news in 2021 when a population explosion in Michigan caused leaf loss in oaks and other trees in infested areas.
The name spongy moth - derived from the common name used in France and French-speaking Canada, "spongieuse" - refers to the moth's egg mass, which has the color and texture of a sea sponge.
Well known in Michigan
Though present in Michigan since the 1950s, widespread spongy moth outbreaks first occurred in the mid-1980s. When populations reach a nuisance level, caterpillars cover tree trunks, decks and just about everything outdoors, and round waste pellets rain down from the trees throughout the day and night.
Suppression programs in the 1990s and early 2000s introduced predators, parasitoids and a fungal disease caused by Entomophaga maimaiga to aid the naturally occurring nucleopolyhedrosis virus in controlling outbreaks.
These control measures remain in the environment, continuing to keep spongy moth populations largely in check and naturalizing infestations into Michigan's forests. Today, spongy moth outbreaks are cyclical, peaking every seven to 10 years. In these years, the virus and the fungal disease spread more easily through dense populations, eventually causing a crash.
What's in a (common) name?
Though it's not clear whether spongy moth populations will boom or bust in your area in 2022, expect to see its new name alongside its scientific name, Lymantria dispar, in future publications and informational materials.
An upcoming NotMISpecies webinar,"New Name, Familiar Pest"(9 a.m. Thursday, April 14), focuses on the unusual history of spongy moth in the United States and here in Michigan, and what you can do to reduce some of the unpleasant impacts of an outbreak. An expert panel including Dr. Deborah McCullough from Michigan State University, Dr. Steven Katovich of the U.S. Department of Agriculture's Forest Service, Susie Iott of the Michigan Department of Agriculture and Rural Development and the DNR's James Wieferich will share tips to help stressed trees recover from leaf loss and options to help reduce the nuisance effects around the home.
Find more aboutspongy moth, including homeowner resources, atMichigan.gov/Invasives. Learn more about thename change from the Entomological Society of America.
Michigan's Invasive Species Program is cooperatively implemented by the Michigan departments of Agriculture and Rural Development; Environment, Great Lakes and Energy; and Natural Resources.
/Note to editors:The original release from the Entomological Society of America,'Spongy Moth' Adopted as New Common Name for Lymantria dispar, was published March 2, 2022.
Accompanying photos are available below for download. Suggested captions and photo credit information follow:
Caterpillar: Though it's now called "spongy moth," the spotted, yellow-faced, invasive caterpillar is a familiar sight in many areas of Michigan.Photo courtesy of Harutu Ovidiu, University of Oradea, Bugwood.org.
Egg mass: The new common name for Lymantria dispar, "spongy moth," derives from the French name, "spongieuse," likening it to the color and rough texture of a natural sponge.Photo courtesy of Karla Salp, Washington State Department of Agriculture, Bugwood.org./