Infestation of Thousands of tiny caterpillars


My lovely multi stem silver birch has been stripped of leaves by thousands of little caterpillars. They are everywhere!

They're about 2cms long mustardy/beigy in colour, with a black head and six little black'feet' near the head. They have  a black stipe down each side.

What are they and how can I get rid of them before they eat more of my little garden!

Thanks in anticipation.


  • DovefromaboveDovefromabove Central Norfolk UKPosts: 42,815

    I suspect they're larvae of one of the sawfles - I wouldn't worry about it - although it may seem that they've done a lot of damage, your tree would've been losing it's leaves in a week or so anyway.

     I'd sit back and watch out  for the blue tits and longtailed tits to find them - they'll have a feast image

    Gardening is cheaper than therapy, and you get tomatoes. 
  • BobTheGardenerBobTheGardener LeicsPosts: 6,357

    They're almost certainly larvae of one of the sawflys which feed on Birch.  They may feed on other trees but almost certainly won't attack garden plants.  If you must use insecticides, look for one which mentions it treats sawfly and caterpillars.  If you want to be organic, either leave them be and wonder at the magnificence of nature or google for 'organic sawfly control'.  A spray made from rhubarb leaves steeped in water may work but be careful as it is equally poisonous to humans (contains oxalic acid.)


    A trowel in the hand is worth a thousand lost under a bush.
  • nutcutletnutcutlet Posts: 24,050

    another sawfly has eaten 2 berberis to skeletons but they'll be back next year

  • PLTWPLTW Posts: 2

    It's definitely striped alder sawfly larvae ... There are thousands of them making my little garden unusable ... They are all over the area where my daughter's sand pit is ... How do I get rid of them and stop them coming back ... I'll try googling the ideas mentioned above ...., thanks For the suggestions..... But if anyone has direct experience of dealing with them I'd love to hear from you! 

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