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Birch Tree Pests

I posted on here a while back about a problem with my silver birch tree which a very helpful poster correctly identified that it was due to me not watering it enough  😖 that issue is sorted now but I think I may now be dealing with a pest or two of some variety.

The first is the caterpillars seen in the attached image, they are completely stripping several branches of their leaves and whilst I've tried to remove them if I've spotted them they are now also on the topmost leaves which I can't reach.

The second is that there seems to be a lot of ants on the tree, at first I thought they might be farming aphids but I couldn't see any but they're clearly attracted to something as there's tons of them. I tried to get a closer look today and could see some small brown things in the branch with the most ants. I tried to take a photo but it's not clear enough to warrant posting. Any thoughts or advice would be appreciated.


  • DovefromaboveDovefromabove Posts: 85,975
    edited September 2021
    I think those are little saw fly caterpillars … nothing to worry about …  just one of the reasons native trees are so important for wildlife … those caterpillars and aphids are important food for bluetits and longtailed tits, wrens and all the other small birds that need to fatten themselves up so they can survive the winter.

    I wouldn’t worry about ants either at this time of year … they’re taking honeydew from the aphids to feed their offspring too … so there’s a new generation of Queens to start new nests next year. 

    As long as the soil isn’t dry at the roots so the ants nest in the rootball … and we’ve tackled the watering issue so it’s not that 😊  

    Your tree will soon be shutting down and losing its leaves for winter.  The insects won’t do any harm now. 😊 

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.

  • FairygirlFairygirl Posts: 53,910
    Yes - nothing to fear. Trees, shrubs and every other plant have pests and insects and all sorts on them. Most do very little, or just some temporary aesthetic, damage.
    If your tree is now doing well, it'll be fine. 

    All part of the 'circle of life'  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • Thanks both, that's reassuring! When I tried to diagnose via Google whether the ants were a problem it suggested it could be a symptom of the tree having some sort of boring pest (as in one that makes holes, not one that isn't exciting :D) but given there are no other signs of this hopefully it is just aphids!
  • FairygirlFairygirl Posts: 53,910
    That's the problem with Google  ;)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
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