The 2020 gypsy moth slow-the-spread program, operated by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) is expected to begin aerial spraying in the second half of May to slow the westward spread of gypsy moth.
Aerial spray treatment dates depend on weather conditions and caterpillar development. A bacterial insecticide is used at some sites when gypsy moth caterpillars are small. A mating disruption treatment is used at other sites prior to adult moth emergence.
Treatments will occur at 58 sites in 18 counties: Bayfield, Buffalo, Burnett, Chippewa, Crawford, Douglas, Dunn, Grant, Green, Iowa, Lafayette, Polk, Richland, Rusk, Sawyer, Trempealeau, Vernon and Washburn.