This is from the Michigan DNR but would also apply to other areas outside of MI. FOR IMMEDIATE RELEASE April 15, 2014Contact: Robert Heyd, 906-228-6561, ext. 3023 or Ed Golder, 517-284-5815 DNR advises caution to prevent spread of oak wilt disease For most people, April 15 is the annual tax-filing deadline. For people like Robert Heyd – and other forest health professionals – April 15 also marks the beginning of the yearly window when oak wilt can be transmitted from diseased to healthy red oak trees. According to Heyd, forest health management program manager for the Department of Natural Resources' Forest Resources Division, oak wilt is a serious disease of oak trees. It mainly affects red oaks, including northern red oak, black oak and pin oak. Red oaks often die within a few weeks after becoming infected. White oaks are more resistant; therefore, the disease progresses more slowly."The normal time-tested advice is to prevent oak wilt by not pruning or otherwise 'injuring' oaks from April 15 to July 15," Heyd said. He added that the spread of oak wilt occurs during this time of year, as beetles move spores from fungal fruiting structures on the trees killed last year by oak wilt to wounds on healthy oaks. As warmer weather melts away snow and ice, the beetles that move oak wilt become active. “Unfortunately, many learn not to prune or otherwise wound trees from mid-April to mid-July only after they lose their oaks to oak wilt,” he said. A common question the DNR is hearing this year is, “Can we push the April 15 day back a week or two because of the cold winter?” Heyd says that isn’t an option. “It doesn’t matter how cold it was this winter,” he said. “It only takes a few 50-degree or warmer days for both the beetles and fungus to become active. We have already had warmer weather in many parts of the state.” Oak wilt has been detected in Alcona, Allegan, Alpena, Antrim, Barry, Benzie, Berrien, Calhoun, Cass, Cheboygan, Clinton, Crawford, Dickinson, Genesee, Gladwin, Grand Traverse, Iron, Kalamazoo, Kalkaska, Kent, Lenawee, Livingston, Macomb, Manistee, Menominee, Midland, Missaukee, Monroe, Montcalm, Montmorency, Muskegon, Newaygo, Oakland, Ogemaw, Oscoda, Ottawa, Roscommon, Saginaw, Shiawassee, St. Joseph, Van Buren, Washtenaw, Wayne and Wexford counties. Although oak wilt hasn't been detected in every Michigan county, Heyd said the need for vigilance is present statewide. Spring is a popular time for people to move firewood to vacation properties and other locations. During this April-to-July period, Heyd said that it's vital not to move wood from oak wilt-killed trees. These trees are often cut into firewood and moved, sometimes many miles from their original locations. Any wounding of oaks in this new location can result in new oak wilt infections as beetles move spores from the diseased firewood to fresh wounds on otherwise healthy trees."With the transport of firewood and other tree-related activities, you have to assume the risk is present, whether you live in metro Detroit or in the Upper Peninsula,” Heyd said. The DNR recommends that anyone who suspects they have oak wilt-tainted firewood should cover it with a plastic tarp all the way to the ground, leaving no openings. This keeps the beetles away and generates heat inside the tarp, helping to destroy the fungus. Once the bark loosens on the firewood, the disease can no longer be spread.New oak wilt sites have been traced to spring and early summer wounding from tree-climbing spikes, rights-of-way pruning, nailing signs on trees and accidental tree-barking (a wound created when bark is removed via impact from equipment, falling trees and other causes). If an oak is wounded during this critical time, the DNR advises residents to cover the wound immediately with either a tree-wound paint or a latex paint to help keep beetles away.Once an oak is infected, the fungus moves to neighboring red oaks through root grafts. Oaks within approximately 100 feet of each other – depending on the size of the trees – have connected or grafted root systems. Left untreated, oak wilt will continue to move from tree to tree, progressively killing more red oak over an increasingly larger area. As more trees die from oak wilt, more spores are produced which contribute to the overland spread of oak wilt.To get more information on the background, symptoms and prevention of oak wilt, visit http://michigansaf.org/ForestInfo/Health/E3169-OakWilt.pdf. To report a suspected oak wilt site, email [email protected] or call 517-284-5895.
Interesting read Dennis. Never heard of it here in Maine. I was thinking that I'd have to consider a "re-location" plan for lots of woodpeckers we have here, if opening up wounds on the bark had to be avoided. Thanks for posting.
I was thinking the same thing about the woodpeckers!.... I wonder if the trees will begin to develope an immunity to this? Lets hope mother nature figures something out.
WOW, Another trees disease. Hope the recent cold long winter helps reduce the spread of the tree harmful bugs & diseases .
I'm pretty sure I had ~3trees succumb to it on my property but Alabama isn't in the map area and the professional foresters at Auburn chalk up the losses that people actually report to drought or other diseases. From what I researched back then the veins of the affected leaves/tree stay green while the rest turns brown - like this one off one of the trees I still need to get out and cut
Thanks Dennis. I have never known this existed if it wasn't for this post! It hasnt hit this area yet, but like all things of this nature, its just a matter of time. As Dave said, hopefully they get some sort of immunity.
That was a good post! Doesn't look like our part of the country is affected (yet). We did have a scare with the asian longhorn a few years ago. One city ended up cutting a large population of trees to keep up withe nastiness.
Thanks for the update Dennis, I was just thinking about that recently wondering when that time frame was.
A few years ago several very large oaks died all at once in a yard down the street from me. I'm well outside that map and I don't know what killed them, but it had to be something that was specifically done to them. A yard full of 100+ yr old oak trees don't all die suddenly while the neighbors remain healthy.
Could have been Harvey Updyke was testing his methods? http://bleacherreport.com/articles/...shes-he-could-kill-toomers-corner-trees-again
So, does "wounding" include cutting down standing dead? Or can they no longer transmit? I had planned to get into the woods and work on a crapton of down and standing dead stuff this spring.
Here in Missouri the conservation department rep recommends you pile all the brush on the stump & burn it to help prevent the spread. The big key seems to be keep the affected firewood well away from the good trees.
You are asking two questions. The article referred to wounding making a LIVE tree susceptible to infection but you're asking if a dead tree can (presumably already infected) still transmit the disease. I would say no if it's been dead for more than a couple of years.. Wood pests tend to either favor live trees or dead trees. The beetle that carries the fungus likely favors live trees that have been wounded (cut or broken).. If that's the case, you should be good cutting standing dead.. Of course there is a caveat... If the standing dead tree was already killed by the fungus, cutting it and transporting the firewood could spread the spores which then could infect other trees.. If you're not sure what cause the standing dead to die, the longer you can wait to cut it, the better (although no necessarily better for BTU's due to spalting and rot) Seems like standing dead can't be infected but can transmit if it was the oak wilt fungus that caused them to die if that makes any sense..
