Oak Wilt

[inspectorwoody]

Wondering what time of year it was you are not suppose to trim oaks due to the wilt problem? Can you remove the whole tree during this time?

Gadget

[Ron Scott]

No cutting or trimming of red oak here during spring sap flow season and until July to be on the safe side. Tree can not be removed if cut and all wood must be completely covered if infected so that the picnic beetle can't get at it to transfer the fungus to another red oak tree.

[Ron Scott]

An Area of Red Oak Rapidly Dieing of Oak Wilt Infection.
Near Lake City, MI; Missaukee County, 8/04.

[Ron Scott]

Oak Wilt Disease Is Dedected In This Northern Red Oak. The characteristic dark oval-shaped fungal pad occurring on the inner side of the bark and on the wood is diagnostic of oak wilt disease in red oak. Missaukee County; 8/04.

[CHARLIE]

Well, I just learned something Ron. I didn't know that Oak Wilt was transmitted by the picnic beetle. Is that the same beetle called a Corn Bug?  They love the smell of latex paint and beer or bourbon. They are a nuisence. The crawl under your hair across your scalp, they crawl down your shirt and they'll even bite, but not very hard. I didn't like them before but really don't like them now. >:(

[beenthere]

Charlie
Found this site that indicates it may be the same (picnic=corn).

http://fciig.ifas.ufl.edu/frsapbe.htm

[Ron Scott]

Yes, I believe that that is the same beetle. It is the common picnic bettle in the Nitdulidae family. It is the primary carrier of oak wilt disease.

[SwampDonkey]

That's a shame there's a major pest of the red oak, keep it down there away from mine. We haven't enough red oak already. Always some bug for everything we want to grow.  : I have to read up on this little bugger.

Thanks for sharing info, Ron and all

[Ron Scott]

Controlling Oak Wilt.

A 5 foot vibrator plow is used to severe the root system of red oak trees infected with Oak Wilt. The plow must go to at least a 5 foot depth for effective control against the infected area.

This contract unit is being used on Michigan DNR land; 8/04.

[Tom]

What does the plow do to control Oak Wilt?

[Ron Scott]

Oak Wilt is transferred through the root systems from tree to tree. The vibrator plow cuts off the root systems to prevent transfer of the disease from infected trees to those not yet infected; 8/04.

[Ron Scott]

Controlling Oak Wilt. More thatn 80% of the time oak wilt spreads from one oak tree to another through root grafts between neighboring trees. Forest health experts recommend trenching to sever existing root grafts to control the spread of oak wilt in this manner.

[Reddog]

We have some property of a friends by Fife lake to do some control on. Lucky( or not) he has two vibratory plows avalible. When I told him he gets to ride a around the woods with em. His comment was great you know how these things shake going thru roots. :D I see by some updated flyers to hold off until dormant if possible, October. My question is there any update to Ron's imput from 2004?

[Ron Scott]

I don't have any further updates, but be sure that the vibrator plow can go at least 5 feet deep.

You might check for further information with the local conservation district forester or Michigan DNR for any further updated information.

[Mike_Barcaskey]

in PA, elective pruning should only be done from the start of November to the end of February to avoid beetle transmission of oak wilt.
of course hazardous situations should be addressed any time.

If you must prune from March to October, use clean tools and imediately pait the cut with a product like TreeKote or a non-toxic latex paint. this is the only time painting cuts is recommended.

[Riles]

Just to clarify, the pruning has nothing to do with the beetles. Both beetles and contaminated tools spread the fungus and both are minimized when the fungus is dormant in the fall and winter (it's usually better to prune when the tree is dormant too).

The jury is still out on whether cuts should be painted or not, with experts going both ways. Obviously, the advantage is in blocking the fungus out from a common infection point, but it only works when you use the right material, do a good job, and don't trap anything else in with the paint (you need a proper cut, too).

You're dead on with sterilizing the tools between trees.

[Ron Scott]

MSU Researchers at Forefront of Efforts to Halt Spread of Oak Wilt
Michigan State University, Apr. 17, 2023
Michigan State University is on the frontlines of research and management efforts to stop the spread of oak wilt, a fungal disease that has killed thousands of oak trees across the state, impacting more than 70% of Michigan's counties.
 

READ MORE

[Ron Scott]

MICHIGAN DNR

During the period between April 15 and July 15, beetles actively carry spores of fungus from tree to tree, meaning oak trees are at high risk for infection with oak wilt. Oak trees with wounds in their bark are susceptible to the disease, which can weaken white oaks and kill red oaks within a few weeks.
If you have an oak tree that gets damaged during the high-risk period from April 15 to July 15, immediately cover all wounds with tree-wound paint or latex-based paint. Painting tree wounds is not recommended for other trees species as it can reduce the effectiveness of the healing process.
Besides being carried by the nitidulid beetle, which is active in spring and early summer, oak wilt also can spread from tree to tree through roots that are grafted or grown together underground. Spores also can be carried long distances to living trees when you move firewood cut from an infected tree and beetles pick up the spores. Oak wilt can kill some oaks within weeks.
First identified in the Midwest during the 1940s, oak wilt was confirmed in Michigan in the early 1950s. It also has been identified in Menominee, Dickinson and Iron counties in the Upper Peninsula. Trees in the red oak family are most susceptible to the disease. These include black oak, northern red oak and northern pin oak - all have leaves with pointed tips. Trees in the white oak group have rounded leaf edges and include white oak, swamp white oak and bur oak. These trees are better able to block spread of the disease through the entire tree, preventing rapid death.
Symptoms of oak wilt most often appear from late June until Sept. Affected trees will suddenly begin to wilt from the top down, rapidly dropping leaves, which can be green, brown or a combination of both colors. Left untreated, oak wilt will continue to move from tree to tree through grafted root systems. As more trees die from oak wilt, more fungal spores are produced, which allows the beetle to carry the infection to new locations.
Firewood cut from infected trees can harbor the fungus, so don't move firewood from one place to another. If you suspect your firewood is infected by oak wilt, you can help slow the spread by burning it, chipping it or debarking it before April.
To minimize the risk of oak wilt infection caused by logging damage, the DNR restricts cutting of red oak trees on state land between April 15 and July 15.
If you suspect a tree has oak wilt. Report infections using an interactive map. Contact a local DNR forest health specialist for more information or to ask a question.

Visit michiganoakwilt.org for a listing and more information.

[Jeff]

July 15th???  Aint that a tad early?

[Otis1]

The Wisconsin DNR uses July 15 also, maybe life cycle of the carrier bug? Probably to prevent spreading by insect rather than root grafting. 

Seems like it came through central and southern Wisconsin a few years ago pretty hard. I see some big dead red oaks but I'm also seeing plenty of healthy younger stuff. 

[Ron Scott]

'Be Aware and Vigilant': Oak Wilt Latest Threat to Our Forests (CAN)
MidlandToday, July 11, 2023
The Nature Conservancy of Canada is sounding alarm bells about oak wilt, a fungal disease emerging as a major threat to oak trees that has been discovered on one tree in Springwater Township, in a residential area near Midhurst, just north of Barrie, and in Niagara Falls. Read More

The E-Forester

[Ron Scott]

Michigan's UP

Oak wilt identified in Pentoga Park | Iron River Publications, Inc.. - Iron County Reporter & Shopper's Guide