**Laimburg Research Centre** announces a PhD scholarship for the PhD program "Mountain Environment and Agriculture” in collaboration with the Free University of Bozen-Bolzano, under the supervision of Prof. Sergio Angeli and Dr. Silvia Schmidt, on the following topic:
**The role of semiochemicals in the tritrophic-interaction and the intraspecific communication of Eriosoma lanigerum and Dysaphis plantaginea: exploring new possibilities for the development of sustainable pest control measurements**:
**Description of the topic**:
The research project focuses on investigating the role of semiochemicals in the tritrophic interactions involving apple trees, the woolly apple aphid (_Eriosoma lanigerum_), and the rosy apple aphid (_Dysaphis plantaginea_). These aphid species are significant pests of apple orchards, causing substantial damage to branches, leaves, and fruits, ultimately reducing yields not only during the initial outbreaks but also in subsequent years. They overwinter either as durable eggs or colonies on apple trees, perpetuating their life cycle and establishing themselves as persistent pests throughout the lifetime of an apple orchard. The pest management relies mainly on synthetic insecticides treatments. During last years a remarkable increase of damages has been registered for the woolly apple aphid, also due to the recent withdrawal or restricted use of certain broad-spectrum insecticides. The study aims to explore how semiochemicals mediate both interspecific and intraspecific communication among these aphid species, their host, the third tropic level (natural parasitoids and predators), with the goal of developing new sustainable pest management strategies for integrated as well as for organic farming. Specifically, the project aims to achieve the following objectives: - Identification of possible alarm pheromones in the two apple aphid species, namely, rosy apple aphid and woolly apple aphid: - Identify the headspace composition of aphid volatiles considering the blend of volatiles released by both apple aphid species, and to characterise them for intraspecific communication.
- Identification of Herbivore-Induced Plant Volatiles (HIPVs) involved in the interaction between apple trees and woolly apple aphids. Compare the obtained information with apple HIPVs already characterised. 2. Determine the behavioural effects elicited by putative alarm pheromones on receiving aphids in laboratory and semi field trials. 3. Investigate the effect of essential oils as botanical insecticides, containing high quantity of bioactive volatiles, in field trials to evaluate their potential for pest management of apple aphids. **Contract duration: 36 months, tempo pieno, Start 1**st** November 2024** **Additional information**:
A major part of the work for this PhD scholarship will be carried out at Laimburg Research Centre in Vadena/Pfatten (Bz). HP