
Numerous spongy moth egg masses on an oak tree in Walworth County. / Photo Credit: Bill McNee, Wisconsin DNR
By Bill McNee, DNR Forest Health Specialist, Oshkosh;
Bill.McNee@wisconsin.gov or 920-360-0942
Forest managers planning silvicultural treatments in stands susceptible to spongy moth (Lymantria dispar) – such as those containing many host species, including oak, birch, aspen and basswood – are encouraged to conduct annual egg mass surveys before treatment.
Surveys make it possible to predict if heavy defoliation is likely. If more than 30 egg masses are found in a sample area – a circle with a 37-foot diameter – then heavy defoliation is expected in the spring, and management activities should be altered or delayed until an outbreak has ended. Continue reading “Harvest Timing Affected By Spongy Moth”