Cuckoo spit - closeup, Heesch, Netherlands
During the nymphal stage of some froghopper species (superfamily Cercopoidea), they produce foamed-up plant sap as protective cover against parasites and other threats.
This could be the work of Philaenus spumarius specifically, a species that is abundant here.

No species identified
The species on this photo is not identified yet. When signed in, you can identify species on photos that you uploaded. If you have earned the social image editing capability, you can also identify species on photos uploaded by others.
By Ferdy Christant
All rights reserved
Uploaded Jun 10, 2020. Captured May 9, 2020 14:56.