Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Cosmopterix orichalcea is a moth of the Cosmopterigidae family. It is known from most of Europe (except the Balkan Peninsula) east to Japan. The wingspan is about 9 mm. Adults are on wing from August to May. Then the larva hibernates outside of the mine in a hibernaculum. The larvae feed on Anthoxanthum odoratum, Festuca arundinacea, Hierochloe odorata, Milium species, Phalaris arundinacea and Phragmites australis. They mine te leaves of their host plant.