Project properties
Title <b> NEW for 2025!! The plant-mediated ecological effect of parasitoids and their symbionts </b>
Group Entomology, Laboratory of
Project type thesis
Credits 24-36
Supervisor(s) Sarah Kalisvaart, Erik Poelman
Examiner(s) Erik Poelman
Contact info sarah.kalisvaart@wur.nl
Begin date 2025/04/01
End date 2025/11/01
Description Parasitoid wasps are commonly used as biocontrol agents. A lot of research has been done on how the environment influences these wasps. For example, plants execute “a cry for help” when under herbivore attack to attract the wasps to help with the infestation. However, what happens after these little helpers arrive is largely unknown. How do parasitoid wasps influence the plant response, and how does this then affect the community around it?

Cotesia glomerata is a parasitoid wasp that has a mutualistic symbiosis with with Cotesia glomerata polydnavirus (CgPDV). It infects is caterpillar host Pieris brassicae with CgPDV, resulting in physiological changes in the caterpillar that influence the defensive response of its food-plant.
So far, it is known that plants associated with CgPDV-infected caterpillars repel the moths of Plutella xylostella and attract hyperparasitoid wasps of Lysibia nana. These little parasitoids therefore already seem to have an important ecological impact that so far has been largely overlooked!

<b> The project </b>
In 2025, I could use your help to figure out how Cotesia glomerata, through changes in its host Pieris brassicae, influences the behaviour of other parasitoid wasps. I wnat to find out how the indirect plant response (volatiles) changes due to the physiological changes in the feeding caterpillar. Then, I want to know how this change in volatile blend influences the behaviour of other parasitoids; will these other parasitoids be more attracted to the plant, or rather shy away? If you pick this thesis, you will get the opportunity to combine exciting lab work with behavioural studies.

<b> What you will learn: </b>
-Running your own greenhouse experiment
-Dissetion of parasitoid wasps to extract venom and virus
-Micro-injection of caterpillars with venom and virus
-Conducting behavioural studies in the y-tube
-Possibly isolate and analyse plant volatiles

<b> Research questions: </b>
- How does C. glomerata parasitism, through changes in the caterpillar host, influence the preference of secondary parasitoids through plant mediated means?
- What role do CgPDV and venom play in this effect?
- How is the indirect plant response (volatiles) altered?
- Can this possible change in volatile blend explain the observed parasitoid behaviour?


If you are interested or want to know more, please email sarah.kalisvaart@wur.nl, I would be happy to answer any questions you have.
Used skills work in the greenhouse, parasitoid-plant interactions, plant stress response, lab work, molecular lab, ecological lab, behavioural lab, ecological interactions, volatile analysis, behavioural analysis
Requirements For doing a MSc-thesis or internship at Entomology, the following requirements apply: ENT-30806 + a second ENT-course (preferably ENT-30306 or ENT-50806 or ENT-53806). As an alternative for the second ENT-course, PHP-30806 or BHE-30306 can be selected.
Note: these requirements do not apply for MBI students; MBI students should check the requirements for doing an ENT MSc-thesis or internship in the study programme of their specialisation.