A dense patch of Japanese stilt grass growing within a forest. / Photo Credit: Wisconsin DNR
By Carter Hellenbrand, Invasive Plant Field Specialist, Fitchburg;
Carter.Hellenbrand@Wisconsin.gov
Note: This is the fourth installment in the Forest Health News “Invasives Spotlight” series, a monthly series of Forest Health News articles.
What has stilts, is green in the summer and reddish-purple in the fall? Japanese stilt grass!
Young larvae of aspen leaf beetle feed on the undersides of aspen leaves. The arrow points to the cluster of eggs that produced the larvae. / Photo Credit: Wisconsin DNR
By Linda Williams, Forest Health Specialist, Woodruff;
Linda.Williams@wisconsin.gov, 920-360-0665.
Aspen leaf beetles have recently been spotted defoliating young quaking aspen trees in Vilas and Oneida counties.
Both adults and larvae will feed on aspen leaves. The defoliation level detected was light to moderate.
Continue reading “Aspen Leaf Beetle Defoliation Found In North”
Messy webbing filled with frass (droppings) and pieces of needles are signs of pine false webworm feeding on this young white pine. The arrow points to a pine false webworm larvae. / Photo Credit: Wisconsin DNR
By Linda Williams, Forest Health Specialist, Woodruff;
Linda.Williams@wisconsin.gov, 920-360-0665
Pine false webworm (Acantholyda erythrocephala) is not a very common insect in Wisconsin, though it is present. They prefer to feed on white pine in Wisconsin, though reference materials say they will also feed on red pine, jack pine and Scotch pine.
Damage was reported as “minor” in the central part of the state from 1953 to 1961. Later, in 1995, 1997, 2002, 2004 and 2006, it was once again observed as a minor pest feeding on red or white pine in the central part of the state, particularly Portage, Waupaca and Waushara counties. In 2024 and again this year, a few scattered young white pine were observed being significantly defoliated in Oneida and Vilas counties.
Japanese beetles defoliating a basswood leaf. / Photo Credit: Wisconsin DNR
By Linda Williams, Forest Health Specialist, Woodruff;
Linda.Williams@wisconsin.gov, 920-360-0665
The Japanese beetle (Popillia japonica) is an invasive insect that feeds on many plant species. The adult beetles “skeletonize” leaves by eating the material between the veins.
Adult Japanese beetles feed on the flowers and leaves of more than 300 plant species, including trees, shrubs and herbaceous plants. Forest trees can be defoliated, with open-grown or edge trees suffering the highest defoliation rates.
Continue reading “Japanese Beetle Populations Still Building In The North”
Hemlock branches show missing needles, and needles with feeding damage, as the result of spruce budworm infestation. / Photo Credit: Wisconsin DNR
By Linda Williams, Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov, 920-360-0665
Spruce budworms are finished feeding for the year, but the damage is still being noticed. That’s especially true in areas where defoliation was severe, such as northeastern Oneida County and southeastern Vilas County.
Spruce budworm prefers to feed on balsam fir and spruce, but in areas with very high populations and severe defoliation, they will also feed on hemlock and tamarack.
Tamarack trees showing the effect of larch casebearer defoliation. / Photo Credit: Wisconsin DNR
By Linda Williams, Forest Health Specialist, Woodruff;
Linda.Williams@wisconsin.gov, 920-360-0665
Earlier this spring, scattered areas of tamarack in North Central and Northeastern Wisconsin showed tan or light brown foliage. Sometimes that is due to frost, but this year it was the work of an insect called larch casebearer.
As the foliage started to expand this spring, the larch casebearer became active and began to feed. The tiny caterpillars mine out the needles of tamarack and use them as “cases” to protect themselves, thus their name.
Continue reading “Tamaracks Busy Refoliating After Larch Casebearer Defoliation”
Alex Hornung, Wisconsin DNR Forest Health specialist for Central Wisconsin, discusses the tree disease phomopsis with Chief Forester Heather Berklund during a site visit near Minocqua in July 2026. / Photo Credit: Wisconsin DNR
By Art Kabelowsky, DNR Forest Health Communications, Fitchburg;
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167
Alex Hornung, the Wisconsin Department of Natural Resources Forest Health Specialist for Central Wisconsin, will discuss oak wilt biology at a workshop this month.
Hornung will take part in a Wisconsin Forestry Center/Wisconsin Natural Resources Foundation workshop on oak wilt biology and management, focused on information for landowners and the public. The discussion will take place from 1 to 3:30 p.m. Tuesday, Aug. 18, at Schmeeckle Reserve, 2419 N. Point Drive, Stevens Point. She will be joined by Dr. Holly Petrillo, Professor of Forestry at the University of Wisconsin-Stevens Point.
Continue reading “Forest Health Staffers Plan Public Appearances”
By Nicolle Spafford, DNR Urban Forestry Grant Manager
Nicolle.Spafford@wisconsin.gov or 715-896-7099
Photo Credit: Wisconsin DNR
As of July 1, 2026, cities, villages, towns, counties, tribes and 501(c)(3) nonprofit organizations in – or conducting their projects in – Wisconsin can apply for a regular or startup 2027 Wisconsin Department of Natural Resources (DNR) Urban Forestry grant.
Regular Urban Forestry grants range from $1,000 to $25,000 and grant recipients must match each grant dollar for dollar. These grants fund projects that improve a community’s capacity to manage its trees (e.g., management plans, ordinances, staff training, tree board development, inventories and public education) and projects that help conserve, protect, expand or improve the urban forest resource (e.g., planting, hazard tree removal, pest control). Continue reading “2027 Urban Forestry Grants Now Open”
By Patricia Lindquist, DNR Urban Forestry Coordinator
Patricia.Lindquist@wisconsin.gov or 715-574-1314
Parks staff Dave Blohowiak and Dawson Boettcher plant a quaking aspen at Fleetwood Park. / Photo Credit: Wisconsin DNR
As a long-time Tree City USA (43 years) and frequent Growth Award recipient (14 years in a row!), Manitowoc has a deep-rooted tradition of supporting urban forestry. After the emerald ash borer was detected in Manitowoc County in 2016, the city redoubled its efforts. Hundreds of dead and declining ash trees have been removed, and thousands of diverse, pest- and disease-resistant trees have been planted to replace the lost canopy.
Manitowoc utilizes a variety of programs, methods and funding sources to plant trees. Read on to learn more about their creative, multifaceted replanting strategy. Continue reading “Community Spotlight: Manitowoc’s Multifaceted Replanting Strategy”
By Olivia Witthun, DNR Urban Forestry Coordinator
Olivia.Witthun@wisconsin.gov or 414-750-8744
Congratulations to the latest class of Wisconsin Community Tree Management Institute (CTMI) graduates! The CTMI wrapped up its sixth cohort mid-June.
CTMI is an advanced training course designed specifically for people responsible for urban forest management who do not have a degree and/or experience in urban forestry. Conversely, they may have technical skills but lack leadership and management experience.
Over six days of intensive training, students acquired the knowledge and skills needed to manage municipal trees and green space. Their exposure to various teaching perspectives gave them a well-rounded 38-hour training experience. The retreat-like setting created by the small class size and interactive learning curriculum reinforced the focus on support-network development with other students, staff and instructors. The capstone of the institute required each student to complete an applied project that benefited their community by utilizing their new skills and knowledge. Continue reading “Students Graduate From The Community Tree Management Institute”
