Froghopper

This is Cercopis vulnerata, one of the largest, and certainly the most distinctive, froghoppers found in the UK. Given its striking colours and wide distribution, I'm surprised I don't see it more often. The froghoppers are also known as spittle bugs due to their habit of surrounding the nymph stage with a protective mass of bubbly foam, known to all country people as 'cuckoo-spit'.