Maybe pinhole borers? I assume they will attack peach trees?
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Oh, no, I think you definitely figured out the problem, but it’s bad news 
Ambrosia beetles. You have to spray to protect lots of other trees they like, too, unfortunately! I hate them with a fierce passion because of how deadly they are
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Should have been shothole borer, not pinhole.
@SpudDaddy Yeah, I think I might have seen these in my tulip magnolia because it didn’t die (and I didn’t see the strings of sawdust). The pinholes are the same size, if so. The symptoms of what the tree is doing and the time of the year is what makes me think it’s the bad ambrosia kind of borer. Last year I had them starting in early spring.
Thank you guys…so I was reading up on shot hole/ambrosia beetles and it sounds like I’m screwed. Every literature I found says keeping trees healthy is the solution and no chemical treatment available. Only option is to cut down infected trees so the beetle population won’t go high enough to attack healthy trees. 
It can’t be true right? There has to be another way.
The 1st thing to do ASAP is to get some serious spray and spray that trunk and the trunks of your other good trees! You don’t want those hungry beetles flying around at all.
If there were some way to definitely seal up the chambers, those beetles wouldn’t hurt anything later. Spraying kills the ones that visit now, but the ones in the tree are the problem for breeding/population later. I’ve wondered if superglue would work?
That’s the quandary when thinking about keeping the tree, unless you can cut it below their holes and still have good tree left. If so, do that and dispose of the bored-in parts, definitely.
As far as how the tree itself will do if you keep the top, it’s the ambrosia fungus that kills its ability to use water, etc. Mine both died, but mine were figs that were either small or that died to the ground in winter, so fewer stores of nutrients than your peach.
I read in another thread that wood glue in the holes can take care of existing larvae. Even though that won’t save the tree, it would reduce the beetle population. I’ll try that.
Any suggestions as to what to spray for preventing attacks on my healthy trees?
If I cut down the trees below the holes, I’ll have to cut down LOW. Pretty much get rid of entire tree. So I do want to spray and do the wood glue and see if it recovers.
I just used Sevin (on the trunk only) often and it worked last year. I had them come visit one fig for a while because I didn’t get all its wood out (letting it grow suckers to cut off and root) and it killed them each time they visited.
This year I haven’t seen any (thank God!) and I have fruits this season, so I’m using malathion or acetamiprid, depending on what I’m spraying for regular fruit insects on the different trees. I’ve had heavy fruit insect pressure, so I’ve used insecticides on them since petal fall.
Oh, but start earlier than petal fall next year for this, btw. Last year it was FEBRUARY that mine started getting hit! That’s earlier than I was ever going to use an insecticide, but not any more.
And cut out any bad wood before then. Damaged wood puts off a scent they are attracted to. Then later they will eat good wood too, as long as they’re there, I guess. I had been letting my figs leaf out before I cut the winter-damaged wood off, but that’s no good around this beetle.
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I was reading about how to protect my for now healthy trees from shothole borers/ambrosia beetles and it looks like these 3 products could work. I’m not sure if there is a less harsh option for this. Does anybody have experience with these?
@Drew51 @mamuang @fruitnut @Olpea @alan @Cafeaulait @scottfsmith
Anybody else? Pls comment.
Cypermethrin
Permethrin
Deltramethrin
Permethrin is a fairly safe product, it is used to kill lice on humans, can be applied as a topical medication. It can kill beneficial insects and bees, so use with caution. As for insecticides, it’s a fairly safe one to use. I have no experience with the others.
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Sorry, I don’t use any if those chemicals. The one I use Triazicide has not worked with some people here. I use it at minimal.
@Olpea is very knowledgeable about chemicals.
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Are you talking about harsh to bees or like to pets, etc? I don’t let my dog right up by the trees, so I go with harshness to bees when possible.
I thought acetamiprid was a good(ish) option there, so I use it on the trunks of trees not attacked. For the attacked ones, I use something stronger in killing the awful things (Sevin) locally on the holes and such. Imidicloprid is the stronger one in acetamiprid’s class, but it’s worse on bees too.
Ortho has a Flower and Vegetable spray with acetamiprid that’s easily available.
I’m not really familiar with using the permethrins. I used one combo on the very base of one tree once and it attracted bees!! It was copper, sulfur and a permethrin, a “garden dust” product from Lowe’s. That was awful. I washed it all off once it became clear that they were actually attracted in numbers. I don’t know what attracted them, but I’m gun-shy to use any permethrin again.
Here’s the bulletin I used to try to decide. I don’t know that it’s the most authoritative, but they know more than I do, lol:
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Susu,
You may be aware those you listed are all pyrethroid insecticides (class 3 IRAC). They are all sodium channel modulators and, as I understand it, open the sodium channels on nerve membranes, flooding the nervous system with sodium.
I mention this because insecticides are classified by their mode of action.
http://www.irac-online.org/documents/moa-classification/
And generally, (though not always) if you look at efficacy tables for various insecticides (I’ve looked at a fair amount of them) you’ll find that most insecticides in a given class have about the same efficacy on a given insect (again there are some exceptions).
Pyrethroids have about the same efficacy on a given insect. Some of them have a little longer activity, but they should all work about the same in preventing the migration of the ambrosia beetle to uninfected trees (I"m not saying they will all work excellent in preventing migration, but that they will probably all work about the same.)
I’ve used Permethrin, Zeta Cypermethrin, and several other pyrethroids, and don’t see any difference other than perhaps a little difference in longevity. Simple permethrin has a little less longevity than some of the others according to past info I’ve read (UV radiation and heat being the big causes of break down of pyrethroids on the trees) Warrior 2 has a little longer longevity due to the special UV protected microencapsulation, but other than that I think they’re all about the same.
I’m not sure you’re going to be able to get Cypermethrin or Deltamethrin though. I’m not sure those formulations are going to be available without an applicator’s license. However permethrin is readily available in without a license, and that’s a fine product.
As mentioned any pyrethoid is going to be lethal to bees, like most other broad spectrum insecticides. That’s why we use them with care (not spraying flowers or blooming weeds etc.) I’ve read that bees practice avoidance behavior with pyrethroids, so I can’t explain the experience of Cafeaulait with the garden dust, although sometimes garden dusts look like pollen to bees. There have been some hive kills from people dusting flowers with Sevin and the bees picking it up and taking it back to the hive, thinking it’s pollen.
In my experience I’ve never seen bees attracted to pyrethroids, but I don’t use the dust form.
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Thanks Olpea for the detailed explanation. Last thing I want to do is to use something that is toxic to bees. I would be ok with losing half a crop to keep the bees safe and feel good about what I eat. But i can’t lose trees. I just got started.
I will go ahead and get this and hope that this will keep my remaining trees borer-free.
Looking on amazon I found Bonide Pyrethrin. After reading what’s out on internet, my understanding is it’s the same as permethrin, only the way it’s derived is different?
I’m not ready to cut this tree down yet. I’m thinking I’ll cut down the branch that looks worst and keep rest of the tree and hope for best. I will also paint the trunks of all my trees. I should’ve done it sooner.
I’m also going to make a beetle trap to see if beetles are around and when I should spray the trees.
Since I don’t have any fruit anyway I might as well get this under control this year if possible…
Susu,
Pyrethrin is the organic counterpart of synthetic pyrethroids. Pyrethrin is an effective a contact insecticide, but is very short lived. The biggest advantage of pyrethroids is the longevity over Pyrethrin, so Pyrethrin isn’t going to have much residual activity. But you can always apply it more frequently.
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Just wanted to post another update on this tree. I did some surgery the other day. I sprayed immunox inside the borer holes using a syringe. Then I sprayed the entire tree with immunox. Waited for it to dry, painted the trunk. Sprayed Pyrethrin. I was going to fill the holes with wood glue but it turned out not an easy task so I gave up on that.
I also made one of those beetle traps with a plastic water bottle and ethanol. (It didn’t catch anything)
Then I took out one large branch that was clearly dead. With that branch went all of my last year grafts. The tree is now down to a two variety tree.
I let rest of the tree be for now. But the growth hasn’t moved in about 5 weeks. So I think non of this is going to help. It looks like a goner.
I did the same treatments to my other younger trees. Today I found a borer hole on my seedling peach tree as well. Just one.
It sucks to care for a tree for so many years and have it die without one single fruit.
I’m also posting a close up pic of the cut site on the branch I removed. In case anybody can see anything…
If I cut the tree down to the roots, do you think it’ll resprout from the roots? Or it’s too late now? Anybody?