Wisconsin may be seeing its worst spongy moth outbreak in more than a decade

Spongy moth populations may spike temporarily about every 10 years. Outbreaks have been trending upward in the last couple of years, according to PJ Liesch, an entomologist with the Division of Extension at UW-Madison. The DNR recorded 294 acres of spongy moth defoliation in 2021, but around 85,000 acres of trees experienced a loss of leaves last year.