Dear Gerhard, Your VO1' birthday means much more to the world odonatological community than a mere celebration of a landmark in the life of one of the most distinguished workers in our discipline. It is no exaggeration to say that without your initiatives, manyfold input and continuous encouragement neither the SOCIETAS INTERNATION ALIS ODONATOLOGICA (S.I.O.), nor its mainstream journal, ODONATOLOGICA, could have ever reached their present level. Indeed it was only your enthusiasm to bring together the dragonfly workers of the world by means of an international journal, which greatly inspired the foundation of the organisation, and of this and some other S. I.O. periodicals. Whenever dark clouds threatened our community it was your determination, unshakable loyalty and wise advice that helped us to overcome all the difficulties so decisively. Exactly four decades have passed since your first odonatological publication, in 1959. Since then, the development of odonate research in Germany (and not only in Germany!) has been largely influenced by your work. Your popular field guides, published in huge editions and in various languages, brought dragonflies and damseljlies to the attention of countless European naturalists, and triggered and facilitated much of the faunistic research in Europe. The same is true of your matchless photographic work, based on the innovative macrophotographic techniques you have developed, and published in various European and non-European countries. Much of the modern odonatological research in Germany, Spain, Argentina, Chile and elsewhere has been initiated by you and is being continued by your young “students" and collaborators. The value and utility of numerous dragonfly hooks, in the Netherlands, Slovenia etc., has been much enhanced by the inclusion of your unique photographs.