Saturday, June 11, 2011

Small Ermine Moth

Small ermine moth infestations on bird cherry Prunus padus trees reach plague proportions around here every few years - and this looks like being a small ermine plague-year. I hadn't really noticed them until last weekend - I walked past these trees in the Derwent valley two weeks ago and didn't notice any webs then, but a week later the tree was festooned with them

Once the caterpillars begin to grow they feed voraciously - a watched this group strip away half a leaf - and they are constantly moving to new leaves, spinning more protective webbing as they go, until whole branches are sheathed in silk.

12 comments:

  1. We saw about 50 yards of a hawthorn hedge covered by a continuous ermine moth web in the Kent river valley just north of Staveley in Cumbria last Sunday. No sign of caterpillars yet but some of the leaves already starting to wither - perhaps because of contact with the web?

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  2. I think you might enjoy Adam Tilt's blog post on caterpillar webbing here (you will find my links, too, in the Comments section).

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  3. Hi Roger, I wonder if the caterpillars have already pupated?

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  4. Hi Caroline, thank's for the tip-off about Adam's brilliant blog - I've signed up as a follower...

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  5. Thanks for sharing. I have seen webs on bushes here too, maybe some other type of moth.

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  6. I've seen these around a lot but hadn't realised what they were. There are masses of them each year at Low Barns and it's always struck me how specific they are to Bird Cherry. To the best of my knowledge the completely ignore the surrounding trees (ash, sycamore, Common Alder) making the Bird Cherry really stand out covered in webs. I wonder what it is that makes the leaves so palatable.

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  7. I saw something similar a few weeks ago here but forgot to check what species it was; however, I saw on Adam's blog that Keith from Holding Moments says that it is the same thing. Isn't this learning wonderful?

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  8. Amazing creatures these.
    We've hundreds of these around my local lake, and this morning I found a few of the moths left; most have gone now.
    Beautiful little creatures.

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  9. Hi lotusleaf, I guess this must be a fairly common defence mechanism in caterpillars...

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  10. Hi Dougie, I've read that they sometimes feed on hawthorn but I've never seen that...

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  11. I love the way the blogger network works for IDing stuff Toffeeapple....

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  12. It's amazing how quickly they get through their life cycle for another year, isn't it Keith?

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