Funnily enough I have today read the Gardeners World magazine which says to fit them round the bottom of fruit tree trunks to stop winter moths climbing the trees and laying their eggs. Also around tree stakes so they can't climb up them as well. Do you have a lot of fruit trees then?

Thank you Cammomile. I always imagined one should put them higher up, before the trunk started to branch. No, we have not got a very big orchard, (very posh word for a small, very sloping rough meadow) just 15 English apple trees that were hauled across Europe in the roofbox of our car, two pear trees and a quince. All the apricot trees we have ever planted grow exuberantly for a year or two and then die quite suddenly. No-one round here can explain why, but apparently it's quite normal. It hadn't occured to me about the stakes - good point.
I'm going to ask a question about codling moths in a moment, and you seem very knowledgeable, so I expect you'll be able to answer that one, too. They aren't the same as winter moths, are they?

I wouldn't say I was that knowledgeable I read that from Gardeners World magazine. I just googled codling moths and there is quite a lot of info on the web about it. Take a look.