Phalonidia affinitana, the large saltmarsh conch, is a species of moth of the Tortricidae family. It is found in China (Liaoning, Tianjin, Xinjiang), Japan, Korea, Russia and most of Europe. The habitat consists of salt marshes. The wingspan is 11–14 mm. Adults are on wing from June to August in western Europe. The larvae feed on the flowers of Aster tripolium. Larva can be found feeding on the flowers from July to August. In September, they bore down the flower stalk and stem to the rootstock. It overwinters in the roots and pupates in March, either in the roots or in debris.