Red sap at base of peach tree, hole in trunk

Asked April 25, 2015, 7:18 PM EDT

On the base of my peach tree today, I found some mostly red colored sap (see photos) coming from the trunk. It was coming from just under the level of the mulch. Looking around for answers, it looks like peach tree borers may be to blame. I hear they can kill the tree. I also found the white worm/grub in the photo with the sap (though I'm not sure that it's related at all). As I swept away the sap, I noticed a hole (a little smaller than a pencil) that had white stuff coming out. I have sprayed the trees with dormant oil (though I now realize it can't help below the level of the mulch if I have mulch next to the tree...) My questions:

  • Does this appear to be a peach tree borer to you?
  • If so, is there anything that can be done to treat it at this point?
  • If you can't treat it, is it a death sentence for the tree (Should we start planting more peach trees now to replace it if its demise is inevitable?)
  • What can be done in the future to prevent this?
Thank you!

Utah County Utah

1 Response

Hello:

Thank you for including all those pictures; that always helps.

Yes, that is the insect greater peachtree borer. All peach trees produce lots of ooze in response to any wounding or insect feeding. The healthier the tree, the more the ooze. Sometimes, that ooze will push the insect (larva) out of the tree, which looks like happened in your case.

At this point, what you have done is good: remove the sap, kill any larvae, etc. Regarding the small hole you found, you could insert a tiny wire to see if you can kill any other larvae in there. Otherwise, there is noting more to do at this point.

Greater peachtree borer is a moth. The larvae in peach trees will start to pupate into moths starting in early to mid June. The moths will then start laying eggs on the lower trunks of trees; the eggs will hatch, and the larvae will immediately bore into the tree, starting the cycle over again.

So, it is important to prevent any more larvae from entering the tree. Starting around June 15, spray the lower 15-18" of the trunk, plus any exposed roots. Permethrin will be the best option. A good brand is Hi Yield Permethrin. Repeat the spray every 3-4 weeks, with your last one on Sept. 15. (Unfortunately, the moths are around all summer.)

Next year, do the same thing. After that, you can probably get away with just 2 or 3 trunk sprays. But it looks like you'll have to continue protecting the tree for many years. Once the bark becomes very thick, the tree is less susceptible.

If you start spraying the trunk of your tree this year, it should be fine and you shouldn't have to worry about loosing it. You might consider a fertilizer application, too. Make sure it gets enough (not too much) water this summer. Keep all tall weeds away from the trunk of the tree.