The larvae feed on Rhododendron tomentosum but possibly also other plants, because the species has been found in areas of Norway and Sweden where R. tomentosum is not present.
Rhododendron tomentosum, a flowering plant also known as Marsh Labrador tea, northern Labrador tea or wild rosemary
Rhododendron | rhododendron | Rhododendron ponticum | Rhododendron tomentosum | Rhododendron luteum | American Rhododendron Society | Rhododendron vaseyi | Rhododendron subg. Hymenanthes | Rhododendron selense | Rhododendron rex | Rhododendron neoglandulosum | Rhododendron ferrugineum | Rhododendron aberconwayi | MV ''Rhododendron'' | MV Rhododendron | Clerodendrum tomentosum | Calophyllum tomentosum |