If you’ve walked the trails in the Preserve recently, especially around Frautschi Point, Tent Colony, and Raymer’s Cove, you may have noticed buff-colored, suede-like patches several inches in size on tree trunks. These are the egg masses of spongy moth (Lymantria dispar), formerly know as gypsy moth*. Spongy moth is an invasive, non-native insect with larvae that feed voraciously on the foliage of many North American plants. While spongy moth may not kill a tree outright, repeated defoliation can weaken trees, resulting in greater susceptibility to disease and other insect pests.
PJ Liesch, Director of the UW-Madison Insect Diagnostic Lab said last year’s drought conditions helped spongy moth populations increase statewide, including in the Lakeshore Nature Preserve.
Infestations within forested natural areas are a challenge, but actions can be taken to protect urban/landscape trees. For more information visit gypsymoth.wi.gov.