About Psylla alni (Linnaeus, 1758)
Psylla alni (Linnaeus, 1758) is a species of psyllid. Adult Psylla alni reach a body length of about 5–6 mm (0.20–0.24 in). These are relatively large psyllids, with green heads, bodies, and legs, and rather long antennae. On their wings, the costal marginal veins are green, while all other veins are brown. Newly emerged adults are green, but they turn orange, brown, or reddish as they mature. Nymphs of this species are usually covered in white waxy secretions. Fifth-stage preimaginal nymphs reach a length of about 2–3 mm (0.079–0.118 in). This species is distributed across the Palearctic realm, ranging from Europe through Siberia, Sakhalin, Kazakhstan, and the Caucasus. It is also present in the Nearctic realm, in Canada and the United States of America.
