They are exactly that caterpillars happily eating the leaves of your tree and using the gossamer to keep the birds away. There are several things you can do... Simply let them be, they will eat the leaves but, unless it is young the tree will survive. If there aren't many, though I suspect there are, you can pick them off by hand and kill. Use a pesticide to kill them.

Hi, these webs are probaly caused by the Webber moth, cotoneasters suffer problems with the webber moth, julien.

or you could blast said silk areas with a powerfull hose atachment .

If you are anywhere near Ealing, make sure the caterpillars are not those of the Oak Processionary Moth - these should be reported to the local Council because they are a health risk to humans and need to be professionally dealt with, usually by the Local Council. They caterpillars build a silken web nest and look grey striped black - google for pics. There are, though, other more benign tent caterpillars, such as the Ermine Moth.

Gosh never heard of that one before Bamboo... and trust it wont get warm enough for it to come up here.

Usually only occurs on Oaks, as far as I'm aware, MG, and is a pest in the south, but probably not up there.

Phew that is a relief...

thanx i never herd of it either bamboo x .

Hi Bamboo, over in france they are a real problem, and as you drive along the A 79 and A 20 you can see these web nests in the pine trees litterally thousands of them, mile after mile, the catterpillers actually attach themselves together as they crawl along the ground in a single line hence the name processionary, julien.

i havetheanswer . take out the leed caterpiller andthey wont knowwear to go lol .

Oh dear, that's bad news - I was hoping they restricted themselves to Oak trees only, but if you've seen them in pines, well that puts paid to that idea then, Julien.