Alder Spittlebug Aphrophora alni
The nymphs of some cicadas live in what looks like a blob of spit. This protects them from enemies such as birds and spiders. By looking well, you can sometimes catch a glimpse of the larva inside the blob. Once they are adult they leave their protecting bubble to jump about. The whole group is referred to as spittlebugs. The adult certainly is the Alder Spittlebug and it is highly likely the larva in the bubble is the Alder Spittlebug as well, but we can't be certain.