Project properties
Title <B><I>Taste your poison:</I></B> How Monarch butterfly caterpillars choose their host plant
Group Entomology, Laboratory of
Project type thesis
Credits 24-36
Supervisor(s) Alexander Haverkamp
Examiner(s) Bregje Wertheim
Contact info alexander.haverkamp@wur.nl
Begin date 2024/10/01
End date
Description Monarch butterflies are not only known for their long-distance migration, but also for being very picky eaters: Their caterpillars only feed on plants of the milkweed genus (Asclepias) (Agrawal et al., 2021). These plants produce cardenolides as a primary defense, which are highly toxic to most animals including humas. However, Monarchs can not only tolerate these compounds, but they can even sequester them and use them for their own defense (Betz et al., 2024). However, not all cardenolides can be sequestered equally well and monarch caterpillars do show preferences for plants with certain cardenolide profiles.
Despite the importance of monarch butterflies as a model system for insect-plant coevolution, we do not yet know how monarchs can taste cardenolides and if they are able to discriminate different compounds with their chemosensory system.

In this project, we will test whether the taste system of Monarch butterfly caterpillars can detect and discriminate cardenolides from different milkweed plants using neuronal recordings from their taste cells. Additionally, we will perform behavioural assays to validate these physiological findings.

Starting literature:
Agrawal, A. A., Böröczky, K., Haribal, M., Hastings, A. P., White, R. A., Jiang, R.-W., & Duplais, C. (2021). Cardenolides, toxicity, and the costs of sequestration in the coevolutionary interaction between monarchs and milkweeds. Proceedings of the National Academy of Sciences, 118(16), e2024463118. https://doi.org/doi:10.1073/pnas.2024463118

Betz, A., Bischoff, R., & Petschenka, G. (2024). Late-instar monarch caterpillars sabotage milkweed to acquire toxins, not to disarm plant defence. Proceedings of the Royal Society B: Biological Sciences, 291(2017), 20232721. https://doi.org/doi:10.1098/rspb.2023.2721
Used skills - Neuronal recordings (electrophysiology)
- Choice and feeding assays
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 program of their specialization.