we have live oaks here in the hill country in texas. i have a few small ones in a section of the property. Last year we had one of them die suddenly (or it seemed to me). yesterday we used a bobcat to knock the rest of it down and found huge grub worms through the entire thing. also a root to another tree has some bore holes in it and is dead at the surface but not completely just the piece of root exposed to sunlight. another one of the small oaks has some bore holes in it also. but the tree has some leaves. another one close to it also has a base hole (but not looking like bore holes). is it possible that these grubs are killing my trees or did they infest it once it died? how do i treat the others around this area. anyone know how far they will spread out? i have some very large oaks in the same area i do not want to lose to these things. . should i take down the small trees right next to the dead one or can i kill the grubs before its too late. HELP ME PLEASE. i have searched all over the internet calling everyone who deals with trees and pests and no one is helping me. all i hear is they like st augustine grass (which i dont have any of that). Thank You, Missy
(https://forestryforum.com/gallery/albums/userpics/10030/borer.jpg)
This is the tree next to the dead grub infested one.
(https://forestryforum.com/gallery/albums/userpics/10030/grub.jpg)
Missy, I hate to be the bearer of bad news, but it sounds to me like oak wilt got your trees and the grubs moved in after. Sudden death is a symtom of oak wilt. The tree will fine and then suddenly the leaves will yellow, fall of and the tree can be dead in as little as two weeks. The leaves will yellow around te veines first spreadind out to the rest of the leaf. Do a search for this disease on the web. A&M has some good info and also the Travis County Forestry Dept. I never found anything that will stop it or its spread. It hits live oaks really hard and also red oaks. You can spend tons of money trying to get rid of it, but all I have ever seen was it slowing it down a little and loss of the trees anyway. I really hope this isn't your problem.
The grubs move into decayed/wet wood...don't kill the tree.
The small picture of the standing oak appears to have decay from previous injury...maybe fire or being damaged near the ground line. Decay is likely.
LeeB seems to have hit on the reason the trees are suddenly dying too.
I agree with Lee about the grubs. They are not likely the culprit. They are probably secondary opportunists.
They appear to be round headed borers and there are many species of them. They are beetles. They generally have long antenna, at least the length of their body (sawyer beetle) or longer (ponderosa pine bark boring beetle). Some attack live wood, such as maple borer and red oak borer, but rarely kill the tree. Sugar maple is the only known host of maple borer. There are several oak boring species. But it seems that other insects species such as carpenter ants gain entry in the borer holes to cause further damage but only when the trees are in decline, dying or dead. However decay fungus can enter wood borer holes to cause rot.
The best control is make firewood from damaged trees, it seems to be very effective in there control according to the USFS. You'll see sap around fresh wounds and possibly an egg mass near by. There will be tiny frass (bug poop) around the wounds or tree base and slivers of wood where the larva emerge from wintering. Wood peckers are also your friend. Oval exit holes are from emerging beetles that grew to adult stage. The adult doesn't go into the wood, just the larvae.
There ain't very many woodpeckers in the Cental Texas area SD.
You need to import some, the wood bugs are getting thick. Your gonna have Swiss cheese oak. :D
I'd have to export some. I'm an Arkansas hillbilly now. :D
Just don't export that one that Arky painted the bill white on and got all that media attention :D
You sure too much watering draws June bugs? Never heard of that. I know they feed on roots, but why would watering draw them to your yard?
when I water my yard it brings in the armadillos because the ground is easier to root in.
That's a really sad news that your tress are killed by these worms. I think you should use medicine to kill them so that your tree might stay longer.
Gardens alive has a nematode that will go after grubs you mix it in a couple of gallons of water and spray. I have used it a few times.