Peach-tree Borers!



Actually the grub of peach tree borer overwinters under the bark, so that little bugger has been living off your tree since last summer. They have sort of a long life cycle.

Glad you got him! Keep an eye out (as I know you will). One peach tree I dug up this spring had multiple borers in it.


I looked up Pen State info before I saw your post. Yup, those nasties work overtime!!! I will look around again.

I’ve found that overtime, dirt/mulch gets piled up and covers bases of my fruit trees. I need to regularly clear it off, not just for peaches but other fruit trees, too.


I kinda think that it’s way too early :grinning:

@mrsg47 Those darn borers worked way too early.


I don’t get it. Could you have missed it last fall and it slept in your tree all winter? :crazy_face:


Which traps do you use?


not really. As far as I understand, the life cycle of the peach borers,
They overwinter inside of tree trunk, roots, and are active when weather is warm. Then move to nearby soil to cocoon themselves before they transform themselves into moth and fly out to lay eggs on the tree in later summer. I dug up couple of Peach tree bores a month or so earlier this year when the temperature was only in near 40 . Not sure whether I got them all or not, but I will get fewer moths laying eggs on my trees for sure


@mamuang did you spray this tree with insecticide last summer/fall? Which ones? and how many times?

I am trying to figure out if I can get good control of borers via regular spraying, like the one recommended by Penn State for instance.


Last year, I sprayed Triazicide. When I spray my trees, I usually spray around bases of tree trunks, too. But like I said, mulch and dirt tends to drift next to the base of trees and inadvertently protects those sons of the gun.

Yesrterday, I cleared mulch/soil away from tree bases and dug down to expose root flare of all my trees. That’s when I saw jelly goo, under soil line. When poeple don’t look below soil, that’s when they find out about borers too late.

I aleady have Triacizide and have no neem or linseed oil so I’ve used what I have.


I use any trap I can find, I just ordered some on Amazon. Arbico, Peaceful Valley and JM Leonard are other sources. I should order a many years supply, they last several years in the freezer.

When I was getting out my confusion lures earlier today I found I had a pile of Codling Moth traps in the freezer… good thing I had not bought them yet!


As luck had it, I found 3 more borers in the same tree. My poor Autumn Star. Glad that I left the root flare exposed. Saw a bit of jelly goo so I started to dig. Got one borer that was intact, the rest were in pieces. I have no mercy for them.

Can’t spray or soil drench yet. Forecast for rain tonight, freezing rain tomorrow and more rain on Mon. This spring weather in New England is lousy, very long cold winter into spring and wet, too.


This one was still moving when I took pic a minute ago.


Mix your triaz. With nufilm so it doesn’t wash off quickly.


I have used a permethrin dust with good results for greater peach tree borers.
Brand name: (High Yield Garden Pet and Livestock Dust)
In my yard they are a real nuisance. At any given time there are 1/2 dozen of them flying around my nectarine and peach trees. In spite of the high pressure I have only found a couple borers in the trunks the past few years and it is usually happens when I get lazy with my application schedule. The USU extension recommends a permethrin spray but the only thing that I could find labeled for fruits and vegetables was a dust. I will putt my gloves on, dig the soil back from the crown and slap the dust onto the trunk up to about 2 ft. I also dust the soil around the base of the trunk as recommended by USU. I usually apply it 3 times in a season sometimes 4.


I only spray once for borers in August, which for me is the height of
borer moth mating activity, and I haven’t seen a borer in years.


I am having a borer issue in my peaches.

I saw goo, exposed root flare then got the wire out and started poking. I did not find anything like your pictures but I hope I at least broke them up. I have a few questions.

Is it ok to leave roots exposed down to root flare? I read to backfill with river rock vs replacing dirt if borers are active.

I did spray with Triazicide then dusted with Sevin. Does this treatment kill anything already in the bark or tree or should I just continue to keep my eye out for additional goo and poke away?

The bark seems beat up, and dry rotted. Should I grab a wire brush and scrape the old bark out of the way?

Finally (and thank you in advance for your help) it seems one of the trees has goo coming from the bottom of the root flare. I guess a borer may have climbed below and up the base of the tree? Will the spray penetrate enough to kill? I took the nozzle and inverted it, spraying into the base of the root flare but I don’t know how to fix this one.

Any assistance is appreciated as I would like to save the trees.


Poke every nook and cranny. Cut away any rotted wood. Peaches are vigorous and will survive if you kill the bugs. They like to transect through the wood near or under the root flare. Take the pocket knife and clothes-hanger wire and scrape out any and all crud.


In addition to what @Matt_in_Maryland suggested, I would like to add that in my limited experience, eac borer tunnel in at different angle. When you use a hire to poke into a hole, try pushing it in in all direction until you find a real hole that it bores in. It will allow the wire to go deep and kill the borer.

All four borers I found, one went in deep down ( vertically), one straight in deep (horizontal) the other two bore side way with one in quite shallow hole near the bark ( the perfect looking one that was alive when I got it). After all the said, you really need to poke around inside the hole until you could see evidence of pieces of borer on the wire, to be sure it’s dead.



Mamuang is a much better at finding the borers than I. I always had trouble finding them.

You mentioned you are also using insecticides. If you do use insecticides to treat borers, it’s been my experience you wouldn’t have to dig them out. I will put a qualifier on that statement, which is I use Lorsban as a trunk spray and let it puddle a little at the base of the tree, so I am using a different insecticide than you are using.

I don’t think the insecticides we are discussing have any penetrant activity, nor are they systemic. But I think they work because they are so lethal to the insect, it doesn’t take very many molecules (relatively speaking) of the compound to kill the insect. I think they wash in the holes when it rains.

I’ve read that Imidan has kickback activity on plum curculio not because it’s systemic, but because it’s so lethal to the larva, relatively few molecules are required to kill it. Enough of the chemical washes in the egg laying hole to kill the grub.

Whenever I see borer goo, I apply some Lorsban at the base of the tree and the borers are done.


One of my contender peaches I grafted last year failed to leaf out this spring. There was green under the bark but not a single bud opened. It stated to shrivel on the end branches so I pulled it up today. It was obvious what the issue was when I got it out of the ground.


Aww damn