Psyllopsis fraxini is a psyllid which lives within a gall on ash ("Fraxinus excelsior"). The larvae feed on "Fraxinus excelsior". Scarce fritillary larvae only feed on the leaves of ash trees (Fraxinus excelsior) at first. The larvae feed on the leaves of "Fraxinus excelsior" and are considered a pest. The larvae feed on "Fraxinus excelsior" and "Fraxinus ornus". The larvae feed on "Fraxinus excelsior", "Ligustrum" and common lilac. Like the purple emperor this butterfly uses 'master trees', usually European ash ("Fraxinus excelsior"). In Europe, "Fraxinus excelsior" is the main ash species colonized. Ash ("Fraxinus excelsior") and Hazel ("Corylus avellana").