A severe storm on May 16, 2017 left a path of destruction through some woodlands in Barron and Rusk counties. (See DNR news release.)
If you are among the impacted landowners, the Division of Forestry invites you to visit this storm recovery page for advice and links to resources. Your local DNR forester is always a good starting point for assistance.
Posted by Kirsten Held, DNR Forestry Outreach Specialist, Kirsten.Held@Wisconsin.gov
Gypsy moth caterpillar with distinctive blue and red dots
This June, gypsy moth populations may rise to damaging levels in parts of Wisconsin. High numbers of gypsy moth caterpillars are a tremendous nuisance and can strip trees of their leaves. Combined with other stresses, such as drought or attacks by additional tree pests, this may kill the tree. The insect’s favorite food is oak leaves, but it will feed on many other tree species such as aspen, birch, crabapple and willow. You can take action to reduce the number of caterpillars that will feed on your trees, including placing sticky barrier bands on the susceptible tree species. Continue reading “Prepare now – gypsy moth caterpillars return”
The forest health program is in the process of updating some of our publications as Forest Health Fact Sheets. These publications offer biology, impact, prevention and management information about specific threats to forest health. Our new oak wilt fact sheet and hickory dieback and mortality fact sheet are currently available on the DNR’s forest health oak wilt and bark beetle webpages and will be available in the DNR’s online publications catalog in the near future. Enjoy!
Written by: Mike Hillstrom, forest health specialist, Wisconsin Dells (Michael.Hillstrom@Wisconsin.gov), 715-459-1371.
Two UW Extension Garden Facts documents have been updated with the latest information on treating trees to protect them from emerald ash borer. Check out the Homeowner Guide and the Professional Guide.
Written by: Linda Williams, forest health specialist, Green Bay, (Linda.Williams@wisconsin.gov), 920-662-5172.
EAB quarantine map. Counties shaded in tan are quarantined for EAB, green areas are townships and municipalities where EAB has actually been identified.
Emerald ash borer (Agrilus planipennis) continues to be found in new areas. Wisconsin continues to track EAB at the municipality or township level; quarantine counties are shown in tan and infested areas are shown in green on the map.
If you know you have EAB, please contact us with that information so we can verify the infestation and update the maps. If your area:
You can reach both agencies from the menu options when you call 1-800-462-2803.
New county quarantines
New finds in counties already quarantined
Written by: Linda Williams, forest health specialist, Green Bay, (Linda.Williams@wisconsin.gov), 920-662-5172.
Porcupine damage to red pine.
Porcupines and squirrels damage trees by eating the bark. Sometimes they remove large areas of bark on branches as well as on the main stem. On sunny days the pale wood where the bark has been stripped off really stands out in the woods.
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 completely 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 “Porcupine and squirrel damage”
Several reports have recently come in of bright orange slime on trees or on mulch in Brown, Door and Shawano counties. Slime molds and yeasts can make bright colors, usually pink, orange, or yellow. Don’t panic – they don’t harm the tree. Often the orange, slimy areas on trees are associated with sapsucker wounds, where the tree has been bleeding sap on which microorganisms are growing. We see these most during the spring when the weather is moist, but once the weather warms the slime will dry up, leaving just a faint orange tinge to the tree where they were.
Sapsuckers wound trees and return to lick the sap that oozes from the wounds.
Slime molds and yeasts can be orange, pink, or yellow. Photo by: Gerald Vomastic
Written by: Linda Williams, forest health specialist, Green Bay, (Linda.Williams@wisconsin.gov), 920-662-5172.
Northern red oak with many phomopsis galls on the branches and on the main stem.
Phomopsis galls are large, woody galls caused by a fungus and can be unsightly on the branches of trees (people often notice them in the winter when leaves are off). They occur in hickories, maples, oaks and a few other species. In northeastern Wisconsin, I find them most commonly on hickory, but in some areas northern red oaks can be heavily galled. Counties where I’ve seen these large galls on northern red oak include Oconto, Oneida, Shawano and Vilas. Continue reading “Phomopsis galls on northern red oak”
Eastern spruce dwarf mistletoe (Arceuthobium pusillum), is a parasitic flowering plant that can be very damaging to black spruce, although it can also attack other spruces. Occasionally you’ll see it on other species growing amidst spruce such as tamarack, white pine, red pine, jack pine, or balsam fir. Continue reading “Eastern spruce dwarf mistletoe”
Many areas of Wisconsin have had abundant rainfall and prolonged cool temperatures this spring which often leads to leaf and needle diseases. The fungal leaf disease anthracnose is the most common issue we see on hardwoods. Continue reading “Leaf and needle diseases”
