Das Projekt "Auswirkungen der Struktur und des Wasserstatus von Leitgewebe der gemeinen Fichte auf die primaere Anziehung von Borkenkaefern (Coleoptera: Scolytidae)" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Forstentomologie, Forstpathologie und Forstschutz durchgeführt. The following hypothesis is investigated: The release of behaviourly relevant monoterpene-patterns through the intact bark of the stem takes place episodically, and depends on structural, physiological and chemical traits of bark tissues and on microclimatic conditions as well. Special attention is paid: the anatomy, resin duct system, water state, monoterpene content, and temperature, of the phloem, in their topographical and temporal variability within a tree and in their variance due to individual differences. Insects in consideration are Ips typographus and Pityogenes chalcographus.