Archives

Fall Webworm Spins Up Attention

Photo of a web spun by fall webworms seen on a tree branch in Oshkosh in September 2024.

Fall webworm is seen on a tree branch in Oshlkosh on Sept. 9, 2024. / Photo Credit: Bill McNee, Wisconsin DNR

By Bill McNee, DNR Forest Health specialist, Oshkosh;
Bill.McNee@wisconsin.gov or 920-360-0942

The native insect known as fall webworm (Hyphantria cunea) is back in the news.

The caterpillars don’t draw much attention on their own; instead, what catches the eye at this time of year are the large webs (or “tents”) that they create on the tips of tree branches.

Continue reading “Fall Webworm Spins Up Attention”

Pine False Webworm Makes Appearance

A closeup photo shows that pine false webworm eggs look like a string of sausages, displayed here on a white pine needle.

A closeup photo shows that pine false webworm eggs look like a string of sausages, displayed here on a white pine needle. / Photo Credit: Liunda Williams, Wisconsin DNR

By Linda Williams, DNR Forest Health Specialist, Woodruff;
Linda.Williams@wisconsin.gov or 920-360-0665

Pine false webworm (Acantholyda erythrocephala) is not a very common insect in Wisconsin, but damage from larval feeding can occasionally be seen. The insects prefer to feed on white pine in Wisconsin, although reference material says 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. 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, a few scattered young white pine trees in Oneida and Vilas counties were observed with significant defoliation.

Continue reading “Pine False Webworm Makes Appearance”

Listen Up: Forest Health Chats On WPR

Wisconsin Public Radio's logo.

By Art Kabelowsky, DNR Outreach and Communications, Fitchburg;
Arthur.Kabelowsky@wisconsin.gov , 608-335-0167

The members of the Wisconsin Department of Natural Resources (DNR)’s Forest Health team are often asked by media to educate their listeners, readers and viewers about the forest health topics of the day.

Wisconsin Public Radio (WPR) is in frequent contact with Forest Health team members and makes its broadcasts and articles available to the public online.

Continue reading “Listen Up: Forest Health Chats On WPR”

CISMAs Offer Invasive Plants Events

A map of the current Cooperative Invasive Species Management Areas (CISMAs) in Wisconsin.

A map of the current Cooperative Invasive Species Management Areas (CISMAs) in Wisconsin. / Map Credit: Wisconsin DNR

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

When it comes to fighting invasive plants, Wisconsin’s Cooperative Invasive Species Management Areas (CISMAs) are often the first line of defense (and offense).

These regional groups provide a localized resource for landowners looking for invasive plant education, identification support and assistance with controlling invasives on their properties.

With 13 CISMAs operating throughout Wisconsin, these groups accomplish a lot each year. CISMA efforts range from fieldwork outings and landowner education workshops to tool-share programs and day-long, control-based field trips.

Continue reading “CISMAs Offer Invasive Plants Events”

Winter Squirrel Damage Killing Maple Branches

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665

Two photos show maple branches that died recently due to previous damage from squirrels.

Two photos show maple branches that died recently due to previous damage from squirrels. / Photo Credit: Linda Williams, Wisconsin DNR

Have you noticed maple branches suddenly dying this summer?

Sudden mortality of maple branches during the summer in northern Wisconsin is often a result of squirrel damage that occurred in late winter and early spring.

In late winter and early spring, gray squirrels strip the bark of maples to get at the sweet maple sap. When the damage is extensive or severe, entire trees or branches will be killed immediately and will not leaf out in the spring.

Continue reading “Winter Squirrel Damage Killing Maple Branches”

Japanese Beetles Finding New Locations

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665

A closeup photo of Japanese beetles defoliating basswood leaves. The invasive pest is becoming more prevalent in northern Wisconsin.

A closeup photo of Japanese beetles defoliating basswood leaves. The invasive pest is becoming more prevalent in northern Wisconsin. / Photo Credit: Linda Williams, Wisconsin DNR

The Japanese beetle (Popillia japonica) is an invasive insect that feeds on many plant species. The pests “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 Beetles Finding New Locations”

CISMAs Plan Invasive Plant Events

When it comes to fighting invasive plants, Wisconsin’s Cooperative Invasive Species Management Areas (CISMAs) are often the first line of defense (and offense).

These regional groups provide a localized resource for landowners looking for invasive plant education, identification support and assistance with controlling invasives on their properties.

Continue reading “CISMAs Plan Invasive Plant Events”

Japanese Stilt Grass An Aggressive New Invasive

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center
Erika.Segersonmueller@wisconsin.gov or 715-492-0391

The slightly off-center silvery midrib of Japanese stilt grass leaves provides a key to identification. / Photo Credit: Leslie J. Merhoff, University of Connecticut, Bugwood.org

Want an advantage over your taller friends? Try propping yourself up on a pair of stilts. As its name suggests, this is precisely how Japanese stilt grass operates. It uses “stilts” (branching rootlets near its base) both as support and to sprawl over nearby plants.

Japanese stilt grass (Microstegium vimineum) is an invasive, warm-season annual grass. It grows one to three feet tall and has an aggressive, mat-like growth that creates dense patches and discourages native plants from establishing. It is also a prolific seed producer, with each plant producing up to 1,000 seeds that can easily spread over land and water during its growing season.

Continue reading “Japanese Stilt Grass An Aggressive New Invasive”

Jack Pine Budworm Outbreak Subsides

By Paul Cigan, DNR Forest Health Specialist, Hayward
Paul.Cigan@wisconsin.gov or 715-416-4920

Aerial view of jack pine budworm defoliation in jack pine stands in Douglas County during the 2023 outbreak. / Photo Credit: Paul Cigan, Wisconsin DNR

Jack pine defoliation caused by the jack pine budworm (JPBW) continued at mostly light levels this year, affecting stands in the Central and Northwest Sands Ecological Regions of Wisconsin.

In the Northwest Sands, jack pine stands experienced light and scattered defoliation across Burnett, Douglas, Polk and Washburn counties. In the Central Sands, JPBW caused moderate to heavy defoliation across roughly 500 acres of jack pine on county and state forests in Jackson County, east of Black River Falls.

Continue reading “Jack Pine Budworm Outbreak Subsides”

Hemlock Monitored After 2023 Defoliation

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665

Photo showing that hemlock crowns remained thin this summer at a Vilas County plot that saw defoliation by spruce budworm in 2023.

Hemlock crowns remained thin this summer at a Vilas County plot that saw defoliation by spruce budworm in 2023. / Photo Credit: Linda Williams, Wisconsin DNR

Spruce budworm was observed defoliating a stand of hemlock trees in Vilas County in 2023. This stand was revisited in 2024 and although defoliation was only light this year, significant thinning in the tops of hemlocks was noted.

Hemlock is not a preferred host for spruce budworm, and the defoliation in 2023 was due to an extremely high population of spruce budworm in that area.

Continue reading “Hemlock Monitored After 2023 Defoliation”