Controlling Pine Wilt Nematode
Advice on halting the spread of Pine wilt nematode (carried by long horn beetles). January 29, 2009
Question
I have 20 Scotch pines and have confirmed that half of them are infected with the Pinewood Nematode. I took samples from the dying trees and still healthy trees to a lab for testing. They are telling me to destroy the diseased trees. I would like to peel the bark and use the logs to build a small log cabin on my property and maybe have some sawed.
I'm on 10 acres of mostly hardwoods in Michigan. From my understanding the nematode is transported by the long horned beetle. If I remove the bark there should be no reason for the long horned beetle to visit the logs and carry the nematode to my healthy trees, right?
Forum Responses
(Sawing and Drying Forum)
From contributor D:
As you are aware the nematode plugs the xylem tissues of the cambium. This blockage of the xylem, water conductive cells, causes the tree to give off the appearance the tree is suffering from drought. I would think there would be some nematodes in the pine's sapwood as well.
I'd bet good money your pine wood will get visited from the long horn beetle, so I would for sure burn the bark and the limbs of the pine trees. I'd check out something like TimBor and spray the peeled logs and sawn lumber while its green. Drying the wood would also work, but may be impractical in your case.
From the original questioner:
Based on the info from the TimBor website and those that sell it I think it will work and it's not too expensive. I was also told to remove the trees immediately, but why would I want to do that during the months that the beetles are most active? Won't that chase them to the healthy trees?
From contributor D:
The long horned beetles are going to go the other pines anyway. Based on what we know - you should cut down the trees and treat the wood, and burn the other parts.
From Gene Wengert, forum technical advisor:
You must do more than remove the bark - you need to burn it. Indeed, it is likely that the beetles are in more locations than just a few trees that you notice are dead or showing signs of dying. Timbor will work to prevent new infections so long as the logs are not wetted by rain. The rain will wash much of the chemical away. Contact your county forester and he will be able to give you some on-the-ground advice.
From contributor S:
Is the wood from 20 scotch pine trees worth the hassle of dealing with these bugs? Pine logs around here can be purchased for about $250/thousand for decent logs. Pine lumber sells for $350-$500 per thousand. Perhaps it would be better to remove the infected trees and light them up rather than dealing with peeling the bark, chemicals and so on. Just my two cents worth, maybe pine in your area is worth more money.
From Gene Wengert, forum technical advisor:
If you heat the logs, you will destroy the insects and fungi in them. Although we usually heat the entire log to over 130 F, you can probably heat just the outer several inches to sterilize that wood where the beetle would be.
