The Second International Symposium of Odonatology will be held during three days at the end of September or at the beginning of October, 1973, at Karlsruhe, German Federal Republic, The international odonatological society, S.I.O., extends to odonatolegists and dragonfly admirers throughout the world a cordial invitation to join together for the Symposium, The Program Committee hopes to arrange a number of colloquia on topics of current importance. The Symposium will meet at the State Museum of Natural History (Landessammlungen fur Naturkunde) of Karlsruhe, within easy reach of the magnificent Black Forest and the Upper Rhine Valley, where the autumnal dragonflies can still be collected while the meeting will be taking place.