Spongy Moth

Help the United States Department of Agriculture (USDA) stomp out invasive pests this spring! Challenge your detection prowess: Look for spotted lanternfly and spongy moth egg masses on vehicles, trees, and other outdoor surfaces during the winter and early spring.

The spongy moth, (Lymantria dispar), formerly known as the "gypsy moth," continues to spread throughout North America, threatening deciduous trees and impacting humans. This non-native, foliage-feeding insect currently occupies only about one-third of its possible host distribution in the United States. Efforts to reduce its impact and spread represent one of the largest and most successful federal and state agency integrated pest management programs against a forest pest.

This new General Technical Report (GTR), published by the Northern Research Station, synthesizes information about the Slow the Spread Program, its accomplishments, and provides a framework for future landscape-level integrated pest management.
See related resource: National Slow The Spread (STS) Program

Citation: Coleman, Tom W.; Liebhold, Andrew M., eds. 2023. Slow the spread: a 20-year reflection on the national Lymantria dispar integrated pest management program. Gen. Tech. Rep. NRS-212. Madison, WI: U.S. Department of Agriculture, Forest Service, Northern Research Station. 130 p. https://doi.org/10.2737/NRS-GTR-212.

The ESA Governing Board voted unanimously last week to approve the addition of "spongy moth" to ESA's Common Names of Insects and Related Organisms List, completing a process started in July 2021 when the previous name, "gypsy moth," was removed due to its use of a derogatory term for the Romani people. Translation of the French name is based on the destructive forest pest's sponge-like egg masses.

USDA’s Animal and Plant Health Inspection Service (APHIS) is replacing the common name for regulated Lymantria moths. APHIS will replace "gypsy moth" (Lymantria dispar) with "spongy moth" and "Asian gypsy moth" (L. dispar asiatica, L. dispar japonica, L. albescens, L. postalba, and L. umbrosa) with "flighted spongy moth complex." This change aligns APHIS with the Entomological Society of America’s "Better Common Names Project" and the scientific community. Spongy moths are significant invasive forest pests. They can defoliate hundreds of species of trees and shrubs and harm our country’s natural resources.

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) caught 202,300 spongy moths (formerly named gypsy moth) in 10,044 traps this summer as part of the federal Slow the Spread of the Spongy Moth Program. "Wisconsin weather trends have allowed the spongy moth population to grow over the last several years," said Michael Falk, DATCP's trapping coordinator.

Spongy moth is an invasive pest that has been spreading westward since its introduction to North America. Caterpillars feed on the leaves of many species of trees and shrubs, especially oaks, and can cause severe leaf loss when feeding in large numbers. For more information, call (800) 642-MOTH (6684), email spongymoth@wisconsin.gov, or visit www.spongymoth.wi.gov.

In some parts of the state, Vermonters are noticing the return of a disturbing sight in our forests and backyards: masses of spongy moth caterpillars. The Vermont Agency of Agriculture, Food and Markets (VAAFM) and Department of Forests, Parks, and Recreation (FPR) have received numerous inquiries from concerned citizens regarding large numbers of spongy moth caterpillars, Lymantria dispar dispar, (also known as LDD, formerly gypsy moth). While the spongy moth can emerge anywhere in the state, unusually high populations observed last year and again this spring are localized in western areas of Vermont. More information regarding the impacts of spongy moths on trees and forests can be found at https://fpr.vermont.gov/spongy-moth.

Names change marks launch of Entomological Society of America (ESA) effort to review, revise problematic insect common names. The ESA has removed “gypsy moth” and “gypsy ant” as recognized common names for two insect species in its Common Names of Insects and Related Organisms List.

The changes are made in conjunction with the launch of a new ESA program to review and replace insect common names that may be inappropriate or offensive. Entomologists, scientists in related fields, and the public are invited to participate in identifying and proposing alternatives for insect common names that perpetuate negative ethnic or racial stereotypes.