We moved into a new house last year, and this summer we are noticing that the tree is oozing a lot of sap and has began to drop pine needles while other needles are starting to turn a light brown colour. Is this due to disease? I peeled back a couple of the sap lumps to find what looks like lesions in the bark, as you can see in the images.

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bark peeled back

Edit: I peeled back the bark and found this^

Additional context: the tree is in Southern Ontario, Canada

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    @pnuts thanks for the suggestion, will do that tomorrow once it light out again and report back
    – ylun
    Commented Aug 16, 2017 at 0:57
  • @pnuts updated!
    – ylun
    Commented Aug 16, 2017 at 17:33
  • Wow nice find.. what could that be? I jsut went out again and poked around a bit more in that area, and that grub seems to have went somewhere else
    – ylun
    Commented Aug 16, 2017 at 18:18

1 Answer 1


The only thing I can find that fits this damage is Sirex Wasp (Sirex noctilio)? they eat young and old wood and then the tree starts to exude resin from the bark, needles wilt and turn brown...not good. infects: Pinus especially the Monterey pine, Larix-larches, Picea-spruces. In Europe the best thing is to inform the local forestry office- very serious over here, but in Canada? Creamy white larvae (like your photo) and a fungus often follows consuming the resin- quite a mess. not good news- but I hope it helps- could be wrong? I found the possible answer in a book of mine I strangely bought in a petrol station 10 years ago -How to get rid of garden pest and diseases, an illustrated identifier and practical problem solver by Andrew Mikolajski page 162. there's no number for the book itself so it might be out of print but its got fantastic colour pictures, helped me several times although when I was being taught at college to be an arborist this problem never came up? I suppose its very rare in England- never seen it in real life. I had to do a really deep search into my books at home to find anything like this- although I love problem solving- I wouldn't want to have this in my garden- sorry for the bad news if I'm right- however I could be (hopefully)very wrong. hope it helps.


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