UNDATED (KDAL) - The Minnesota Department of Agriculture will host open houses in Duluth on Thursday to explain the treatment plans for gypsy moths in northeastern Minnesota this summer. The moths are among the most destructive tree pests in the country and have been spreading westward from New England over the last decades. The gypsy moths are already common in Wisconsin and are becoming established in the arrowhead of Minnesota. Meetings are planned from 11 a-m to 1 p-m at City Center West, 5830 Grand Avenue and from 4 to 6 p-m at the Duluth Heights Community Center at 33 West Mulberry Street. Gypsy moth spraying will also occur this summer in northwestern Wisconsin and the Wisconsin Department of Agriculture, Trade and Consumer Protection will hold a public meeting Thursday from 11 a-m to 1 p-m at the Hayward City Hall.