The Wisconsin Department of Agriculture announced that 202,300 spongy moths (formerly named gypsy moth) were caught this past year in over 10,000 traps as part of the federal Slow the Spread of the Spongy Moth Program. The agency uses trapping to help track the size and location of moth populations.
"Wisconsin weather trends have allowed the spongy moth population to grow over the last several years," said DATCP Trapping Coordinator Michael Falk. "A lack of extreme cold events has allowed many spongy moth eggs to survive the winter, and a steady trend of warm, dry summers has limited the impact of diseases that normally kill spongy moth caterpillars."
Spongy moth are known to undergo cyclical patterns of population growth and decline that span several years. The population increases documented in 2022 were not unexpected in areas like central-eastern Wisconsin, where spongy moth populations are well-established. In western Wisconsin, rates of spread to uninfested areas remained moderate in the southwest and west-central parts of the state, but were higher than usual in the northwest.
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.
Trapping data helps determine potential sites for the following year's aerial spray treatments.
Categories: Wisconsin, General