Proceedings of the 9th International Symposium on Insect Plant Relationships Jr US and Japan which made Pathologisches Institut der Universität US and Japan which made important contributions to this field and particularly in topics improving the understanding of physiological and pathophysiological roles ofAPN CD13 and DPIV CD26 osmotic and heat shock as well as salt and oxidative stress) This is due to the fact that we decided to produce not only an account of the proceedings but also to publish all contributions as a special volume of the journal Entomologia Experimentalis et Applicata We were pleased and honoured to organise this symposium