Hole in tree with thin white worm / larvae (white oak)

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TylerS84

TylerS84

New Member
Joined
Jun 2, 2018
Messages
4
Location
Michigan
Hello,

I have a seeping hole in my white oak tree (I'm 90% sure it's a white oak, but not 100%). Inside the hole is a thin, about 1" long white worm / larvae. You can't see the worm/larvae in the pictures unfortunately, I was only able to see it using a flashlight.

I did some pruning of the tree in very early spring this year, (late february or early march) and I'm in SE michigan so I think I was ok with that timing. The hole and worm are low on the tree, about 3' up from ground, and not where I've previously pruned etc. I don't know the source of the hole / entry point.

Last summer my HOA forced me to prune some low branches and at the time I sealed those prunes with the black "prune seal" stuff from home depot. Shortly after that pruning I did see larvae of something on the cut (which thankfully I had sealed).

Any suggestions or thoughts? There are several white oaks near this one (my other street tree is a white oak about 30 feet away, and same goes for about 8 to 10 tree's in either direction and across the street.

should I spray an insecticide, or seal type product (recommendations?). I have some of the black "prune seal" stuff with insecticide, but I know generally you're not supposed to use those products. How likely is it I'll lose the tree (shortly or in the future) due to something like this?
 

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ShermanC

ShermanC

ArboristSite Operative
Joined
Jan 25, 2008
Messages
342
Location
Mountain View, AR 2-1/2 hours north of Little Rock
Hello,

I have a seeping hole in my white oak tree (I'm 90% sure it's a white oak, but not 100%). Inside the hole is a thin, about 1" long white worm / larvae. You can't see the worm/larvae in the pictures unfortunately, I was only able to see it using a flashlight.

I did some pruning of the tree in very early spring this year, (late february or early march) and I'm in SE michigan so I think I was ok with that timing. The hole and worm are low on the tree, about 3' up from ground, and not where I've previously pruned etc. I don't know the source of the hole / entry point.

Last summer my HOA forced me to prune some low branches and at the time I sealed those prunes with the black "prune seal" stuff from home depot. Shortly after that pruning I did see larvae of something on the cut (which thankfully I had sealed).

Any suggestions or thoughts? There are several white oaks near this one (my other street tree is a white oak about 30 feet away, and same goes for about 8 to 10 tree's in either direction and across the street.

should I spray an insecticide, or seal type product (recommendations?). I have some of the black "prune seal" stuff with insecticide, but I know generally you're not supposed to use those products. How likely is it I'll lose the tree (shortly or in the future) due to something like this?
The bark in photo resembles poplar not white oak. Look at the leaves around its base then start your effort to identify the tree specie by the leaf description. The USDA has a paperback book of 784 pages about borers and their larva. If you want to save the tree and have money for this, you can go to a website for tree injectors preferably Maujet & Co. to locate a technician to inject insecticide on the buttress roots to kill borers. Maujet makes eleven chemical capsules for treating insects and diseased trees. My mentor for four years in northFlorida was a certified forester and Maujet representative. I’ve never had surplus funds to get into this kind of service for ailing trees.
 

ATH

Addicted to ArboristSite
Joined
Nov 18, 2006
Messages
4,523
Location
Ohio
Probably nothing to worry about - looks worse than it is. Gently cut away the dead bark around the hole, but avoid cutting into live tissue (stop cutting as soon as you see green). Something damaged the tree there. The damage could have been done by the larvae you are seeing (maybe, for example, two-lined chestnut borer which is no uncommon on young/stressed oak trees - how long ago was the tree planted?). Or, the larvae you see could be a bug that just found a sheltered place to lay an egg where the bark was damaged by something else.

I probably wouldn't drill to inject that tree (outside of a few abnormal circumstances). Not that we don't do injections...we do - but to treat one spot, I wouldn't. It wouldn't hurt to spray that area with a little insecticide...but once you open it up, you can probably pull the larvae out. If you wanted to do a systemic insecticide, a soil drench (just right around the base of the tree) with imidacloprid will do a good job controlling many insects except lepidoptera (moths - there are some that bore into trees), mites (more of a leaf problem), and armored scale.

I'd have told the HOA you'll be glad to prune, but in order to protect not only your tree, but all of the other oaks in the neighborhood, it would be negligent to prune during the growing season. Plenty of documentation out there to make that case. But this isn't oak wilt, so that didn't cause what you see here...just saying in the future. However, I'd also say now that you know this is an expectation, plan ahead and prune during dormancy to keep adequate clearance throughout the growing season.

I suspect that is Red oak. Can you get a good picture of the buds (or any left over leaves)?
 
thenne1713

thenne1713

ArboristSite Operative
Joined
May 24, 2008
Messages
177
Location
Memphis
Probably nothing to worry about - looks worse than it is. Gently cut away the dead bark around the hole, but avoid cutting into live tissue (stop cutting as soon as you see green). Something damaged the tree there. The damage could have been done by the larvae you are seeing (maybe, for example, two-lined chestnut borer which is no uncommon on young/stressed oak trees - how long ago was the tree planted?). Or, the larvae you see could be a bug that just found a sheltered place to lay an egg where the bark was damaged by something else.

I probably wouldn't drill to inject that tree (outside of a few abnormal circumstances). Not that we don't do injections...we do - but to treat one spot, I wouldn't. It wouldn't hurt to spray that area with a little insecticide...but once you open it up, you can probably pull the larvae out. If you wanted to do a systemic insecticide, a soil drench (just right around the base of the tree) with imidacloprid will do a good job controlling many insects except lepidoptera (moths - there are some that bore into trees), mites (more of a leaf problem), and armored scale.

I'd have told the HOA you'll be glad to prune, but in order to protect not only your tree, but all of the other oaks in the neighborhood, it would be negligent to prune during the growing season. Plenty of documentation out there to make that case. But this isn't oak wilt, so that didn't cause what you see here...just saying in the future. However, I'd also say now that you know this is an expectation, plan ahead and prune during dormancy to keep adequate clearance throughout the growing season.

I suspect that is Red oak. Can you get a good picture of the buds (or any left over leaves)?
 

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