By Brenna DeNamur, DNR Forest Health Outreach Specialist, Madison, Brenna.DeNamur@wisconsin.gov
The Forest Health Team has made many changes since the spongy moth’s* (formerly known as gypsy moth) new name debut in March. Earlier this month, we launched the new and improved Spongy Moth Portal!
By Linda Williams, DNR Forest Health Specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665 & Paul Cigan, DNR Forest Health Specialist, Hayward, Paul.Cigan@wisconsin.gov, 715-416-4920
Emerald ash borer (EAB) has been detected for the first time in Forest County in the Town of Armstrong Creek and Ashland County in the City of Ashland. The Forest County detection was most likely a natural expansion of other infestations in Florence and Marinette counties.
This Forest County tree was infested with EAB top to bottom. Photo: Wisconsin DNR
The Ashland County detections appear to be isolated infestations likely spread through the transportation of firewood or logs. Several large green ash stands in the City of Ashland show advanced infestation signs.
EAB was first found in Wisconsin in 2008. There are now just seven counties where EAB has not yet been identified. EAB was federally deregulated as of January 2021. In 2018, Wisconsin instituted a state-wide quarantine. This discovery in Forest and Ashland counties will result in no regulatory changes.
Please visit the interactive Wisconsin EAB detections map to see where EAB has been reported. Follow the map’s instructions if you know of an infested area not on the map. Continue reading “EAB Identified For The First Time In Forest And Ashland County”
By Linda Williams, DNR Forest Health Specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665 & Paul Cigan, DNR Forest Health Specialist, Hayward, Paul.Cigan@wisconsin.gov, 715-416-4920.
Spring cleanup is always a busy time in the Northwoods as those with second homes and cabins make the trek northward to prepare for a summer of fun. For many, this will mean cleaning up trees and branches damaged by winter storms.
Large white pines (pictured here) and young birch growing on forest edges were most heavily impacted by winter’s storms. Photo: Wisconsin DNR
Continue reading “Spring Cleaning: Storm Damage Cleanup Brings Oak Wilt Risk”
By Brenna DeNamur, DNR Forest Health Outreach Specialist, Madison, Brenna.DeNamur@wisconsin.gov; Jaqi Christopher, DNR Forest Invasive Plant Specialist, Rhinelander, Jacquelyn.Christopher@wisconsin.gov; & Mary Bartkowiak, DNR Forest Invasive Plant Coordinator, Rhinelander, Mary.Bartkowiak@wisconsin.gov
Spring is here! Invasive plants, like garlic mustard, are often among the first green life to emerge in the new season.
Garlic mustard is an invasive plant that appears early in spring. Photo: Wisconsin DNR
By Michael Hillstrom, DNR Forest Health Specialist, Fitchburg, michael.hillstrom@wisconsin.gov
Black walnut is one of Wisconsin’s healthiest, least threatened tree species. Photo: Wisconsin DNR
Once in a while, the Wisconsin DNR Forest Health Team gets to deliver good news about an emerging insect or disease issue!
Recent research suggests that thousand cankers disease of walnut is not the threat we initially feared when cases appeared for the first time in the eastern U.S. in 2010. Thousand cankers disease is caused by walnut twig beetles carrying a fungal pathogen. The disease has yet to be detected in Wisconsin.
Following its arrival in the eastern United States, the insect’s populations declined. Many stressed urban trees recovered after drought conditions subsided in the impacted areas, and forest trees have fared even better than their urban counterparts. Additionally, walnut twig beetles don’t enjoy Wisconsin winters, as mortality begins in the low single digits Fahrenheit. Perhaps this is why we have not yet found the walnut twig beetle in Wisconsin.
USDA staff cut a ‘bark window’ in green ash to uncover signs of emerald ash borer.
Emerald ash borer (EAB) is an invasive insect from Asia first introduced into the United States in 2002. Since its discovery, EAB has caused tens of millions of ash trees to die and decline. Today, the U.S. Department of Agriculture (USDA) uses ash trees against the pest to help preserve and protect the tree species. They are asking Wisconsin landowners for their help.
Wisconsin landowners have donated live, infested ash trees to USDA’s EAB biological control program. The staff will then use the wood to cultivate EAB’s natural enemies and release them in Wisconsin and 28 other EAB-infested states. The biocontrol staff will need more ash trees to continue producing and releasing these stingless wasps that attack and kill EAB and are hoping more Wisconsin residents will consider donating their ash trees this year.
Continue reading “USDA Biological Control Facility Seeks Ash Trees To Battle Emerald Ash Borer”
By Paul Cigan, DNR Forest Health Specialist
Paul.Cigan@wisconsin.gov or 715-416-4920
Emerald ash borer (EAB) has been discovered in Bayfield County for the first time in both the city of Bayfield and Bayview township to the south. This marks the 63rd out of Wisconsin’s 72 counties to have an EAB discovery since its initial detection in 2008.
Figure 1: First known infested ash tree in Bayfield County with characteristic woodpecker damage (i.e., flecking).
Photo: Wisconsin DNR
Several white ash trees (Fig 1.) were observed in and around a roadside park in the city of Bayfield, and larval specimens were subsequently lab-confirmed. In Bayview, a black ash swamp had several infested black ash (Fig 2).
After introduction, EAB populations remain low for at least several years as most larvae in newly infested, healthy ash require two years to complete their life cycle. The abundance of healthy ash at each site suggests EAB populations have remained low since their introduction at least three years ago. However, EAB will kill ash more quickly as beetle numbers mount and more larvae transform from egg to adult in a single year. Unfortunately, many ash in the area are expected to die within four to seven years based on detection-to-impact timeframes observed from the Superior and Duluth area and research conducted in midwestern states. Continue reading “Emerald Ash Borer Found In Bayfield County”
Contact: Paul Cigan, DNR Forest Health Specialist
Paul.Cigan@wisconsin.gov or 715-416-4920
As April brings a high risk of the often-fatal oak wilt disease, the Wisconsin Department of Natural Resources (DNR) recommends not pruning or cutting oaks from April through July.
Do not prune, cut or wound oaks April through July.
Photo: Linda Williams
By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665
Narrow grooves are left when squirrels chew the bark off a young tree or a branch.
Photo: Wisconsin DNR
In late winter, it’s common to see tree branches that have been freshly stripped of their bark. Damage can be extensive where entire branches, and sometimes entire small trees, can be stripped of bark. This damage, believe it or not, is from squirrels! While primarily found on sugar maples, you can also find squirrel damage on red maples and the occasional oak. So far this year, the damage has been noted in Langlade, Shawano, Oneida and Vilas Counties.
On sunny days, the pale wood of branches where the bark has been stripped off stands out in the forest. This type of feeding can remove enough bark to girdle the branches or the main stem, causing the tree to die from that point to the end of the branch. Branches that are not entirely girdled will continue to grow, and callus tissue will begin to grow over the wounds. If branches are nearly girdled, they may leaf out in the spring only to have the leaves suddenly wilt and die as hot weather hits because the tree can’t move enough water to keep the leaves alive. Continue reading “Squirrel Damage Mayhem”
By Bill McNee, DNR Forest Health Specialist, Oshkosh
bill.mcnee@wisconsin.gov or 920-360-0942
Property owners with healthy, valuable ash trees are encouraged to treat them with insecticide this spring to protect against emerald ash borer (EAB). The pest is currently the most damaging threat to trees in Wisconsin, killing more than 99% of the ash trees it infests.
This ash tree branch in West Allis has been damaged (“flecked”) by woodpeckers feeding on EAB larvae under the bark.
Photo: Bill McNee, Wisconsin DNR
Continue reading “Protect Your Valuable Ash Trees Against Emerald Ash Borer”
