By Ethan Wachendorf, DNR Forest Health Lab Technician, Fitchburg, ethan.wachendorf@wisconsin.gov or 608-273-6276
Have you noticed orange, jelly-like growths on cedars this spring? These growths may look like tiny octopus creatures with legs extending all directions, but they’re actually spore horns caused by a fungus.
Orange jelly-like spore horns caused by cedar-apple rust fungus. Photo: Wisconsin DNR
Continue reading “When It Rains, It Spores! Orange Spore Horns Emerge”
By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665.
Introduced basswood thrips are tiny, invasive insects that feed inside tree buds in early spring. Leaves are then deformed when they expand and can look like frost or wind has damaged them.
An adult introduced basswood thrips on the underside of an emerging basswood leaf. This photo is enlarged under a microscope. To the naked eye, they appear as tiny black specks on the underside of the leaf. Photo: Wisconsin DNR
Continue reading “Basswood Thrips: Tiny Terrors Of Basswood Leaves”
By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665.
White trunk rot (Phellinus tremulae), sometimes called aspen trunk rot, is a fungus that causes decay columns to form in aspen. The fungus enters the tree through branch stubs, wounds or small dead branches that remain on the tree. Perennial conks, or fungal bodies, then grow from these sites.
White trunk rot causes decay in aspen trees. Note the conk (fruiting body) from the fungus on the left side of the pic. Photo: Wisconsin DNR
By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665.
Maples
Have you noticed any maple trees that appear brown or reddish and have fewer leaves than usual? The seeds, not the leaves, make the tan/red color. Those seeds are so plentiful this year that they can easily be spotted from a distance.
Maples with heavy seed crops may appear tan or reddish due to the color of the seeds and having very few green leaves in the canopy. Photo: Wisconsin DNR.
Continue reading “Slow Oaks And Maples With Too Many Seeds And Not Enough Leaves”
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”
