Alder Spittlebug Aphrophora alni

The Alder Spittlebug is a froghopper that feeds on alder and many other trees and shrubs. It is about 2 cm long and relatively common.

Its pattern with two white patches on each forewing is similar to one variation of the Common Froghopper and even to some Neophilaenus campestris but the Alder can be differentiated by the raised "keel" on its face and pronutum.