Chemical Ecology

Various primary and specialised metabolites are transported via the phloem sap in the plant sieve tubes. The chemical composition of the phloem sap can be influenced both by abiotic and biotic environmental factors. In several projects, we investigate the impacts of various environmental factors (e.g., fertilisation, drought, competition, symbioses) on the phloem sap chemistry of different plant species.

Therefore, pure phloem sap is collected, for example using the aphid stylectomy technique and chemically analysed. To understand how phloem-feeding herbivores (e.g., aphids) are influenced by chemical modifications of the phloem sap, we study the performance of aphids on artificial diets varying in chemical composition. Moreover, chemical analyses of aphid honeydew allow insights into the dietary metabolism within the aphids. The overall aims of these studies are to characterise the factors, which are relevant for aphid nutrition, and to understand aphid development on plants in nature