Neophilaenus species can be distinguished as adults from Philaenus spumarius by the more parallel outer edges of the wings when viewed from above (as opposed to the more  convex outline of P. spumarius) and their overall pattern of  markings. They are much smaller than Aphrophora species. 
 
Neophilaenus lineatus is identified by the pale margin of the forewing, backed by a darker line. There is a dark form that occurs in certain populations living on purple moor grass, Molinia caerulea.