Project properties
Title <b> NEW!! THIS SUMMER: 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) Marcel Dicke
Contact info sarah.kalisvaart@wur.nl
Begin date 2024/04/01
End date 2024/12/20
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!

If you do a thesis with me, there are multiple possibilities to choose from:

<b> Field work </b>
Do you like working hands on in the fresh air, but also in the lab? Then this thesis is perfect for you! Starting in May, I will start a project in the field. If you join this project, you will manage your own field experiment. You first infest cabbage plants with differentially treated P. brassicae caterpillars (parasitised, not parasitised, with virus, etc). Then, you will see if parasitoids in the field are differentially attracted to these plants by releasing and recapturing caterpillars. Additionally, you can do some lab work on parasitoid behaviour with the y tube. Can you find the same thing in the field as in the lab?

Research questions:
- How does C. glomerata parasitism, through changes in the caterpillar host, influence the attraction of other parasitoids?
- What role does CgPDV play in this effect?
- Can we find the same phenotype in the field as well as in the lab?
- (How is the volatile blend altered by this?)

What you will learn:
-Setting up your own field experiment
-Combining both lab (behavioural/molecular) and field findings
-Conducting insect behavioural experiments
-Microinjection of caterpillars in the lab
-Potentially look at plant volatiles if interested

<b> Lab work </b>
If you do not like field work but love the subject, I have some good news for you. Additionally to the field project, I also have a project in the greenhouse. In this project, I want to find out how parasitoid wasps, through changes in their caterpillar host, change plant physiology. Additionally, I want to know how this altered plant phenotype affects herbivores that arrive later on the plant. In this thesis, you will get the opportunity to run your own greenhouse experiment and combine it with some exciting lab work! How do herbivores respond to parasitoid presence? Can the altered phenotype you find explain this?

Research questions:
- How does C. glomerata parasitism, through changes in the caterpillar host, influence the performance of secondary herbivores?
- What role does CgPDV play in this effect?
- How is the plant phenotype (glucosinolates/phytohormones) altered?
- (How are plant volatiles altered?)

What you will learn:
-Running your own greenhouse experiment
-Micro-injection of caterpillars
-Herbivore performance essays
-Plant phytohormone and glucosinolate analysis in the molecular lab
-If intersted you can combine it with y-tube work and volatile analysis


If you are interested or want to know more, please email sarah.kalisvaart@wur.nl
Used skills work in the greenhouse, herbivore-plant interactions, plant stress response, lab work, field work, molecular lab, ecological lab, behavioural lab, ecological interactions
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.