Is it true borers hit unhealthy trees?

General Fruit Growing
#1

I’ve never had problems with borers on my peach trees before.

Last year a hail storm caused severe damage to my peach trees with deep wounds that ripped chunks of bark off.

This year, I have extensive borer damage all the way from the ground to the scaffold branches.

I’ve read that borers attack sick trees. Is it true or just a coincidence?

#2

Borers hit everything they find and like

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#3

They don’t discriminate…
In my experience, they attack any tree that is young (never seen it in a 30cm wide walnut or ash for example). In our garden, an older willow is an exception as it has plenty of sap flowing. They seem to prefer juicy to rock hard… Then, the disrupted trees may suffer differently. Some trees don’t seem to notice. I have a crataegosorbus which has damage like it was mauled by a twisted beaver and grows like nothing happened. An ash on the other hand apparently got infedted, grows on like a magic bean, but has a gaping hole in the bark surrounding the entry point.
I think peaches and most stone fruit are more prone to get infected afterwards, though some will flood the hole with resin so you can’t even pull the larva out.
So the difference is in the trees capacity to cope.

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#4

They will attack anything. That being said, already damaged trees are more susceptible to attack, and are more attractive to borers.

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#5

Does the resin kill the larvae?

#6

I am not sure. I would guess that it can drown the larva, but with strong enough flow, you would probably not notice the wood chip confetti that usually announces the borer party soon enough. By that time the larva has either bored it’s way out higher up, or you can’t push a hooked wire in to catch it. I’ve never used more invasive methods to investigate and compromise the tree even more.

#7

Ambrosia beetles are certainly known to attack unhealthy trees and they do bore into the tree, but they aren’t regular borers like the peach borers. I’m hearing more and more people having trouble with ambrosia beetles after a late frost, after grafting or after wet soil causes root rot, which is what brought them to a 80 foot tall oak they took out in my yard.

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