Ron wrote

http://www.bbc.co.uk/cumbria/content..._feature.shtml


They don't seem to do much harm to my Lilies here in Sarf Wales.

I usually just flick 'em off with a fingernail and they don't often
seem to find their way back.

I usually tap them on the head with my size 11s. :-)
However it's the larvae that do the most damage and they can be easy to
miss. They cover themselves with their own excreta and look like bird poo
but usually under the leaves. Look for leaves looking damaged and pull off
(nasty job!) or spray, a few on one plant will eat it completely in a few
days.

--
Regards
Bob Hobden
just W. of London