About the European Alder Spittlebug
Aphrophora alni, the European alder spittle bug, is a species belonging to the family Aphrophoridae. This species is quite common and widespread. It is present in most of Europe, in the eastern Palearctic realm, in the Near East, and in North Africa. It is naturalized in North America.
These 'froghoppers' inhabit dry and moist habitats of lowlands and mountainous areas, forest edges, hedgerows, meadows, gardens and parks, from the lowlands up to mountains at an elevation up to 1,500 metres (4,900 ft) above sea level.
The adults of these large 'froghoppers' reach 9–10 millimetres (0.35–0.39 in) of length, the females are usually slightly larger than the males. The basic coloration of the body is usually brown. Their front wings wear two distinct clear patches on the margins. Head and pronotum have a median keel. The head has a pair of compound eyes and two simple eyes (ocelli). The legs are strongly developed and fit to jump. Tibiae of the rear pair of legs carry several spines.
They can be encountered from May through October on bushes and on several species of trees, especially willows (Salix species), birch (Betula... Wikipedia →