Mr A.J. (Bram) Knegt MSc
Faculty of Science
Institute for Biodiversity and Ecosystem Dynamics
Science Park A
Science Park 904 Room number: C3.218
1090 GE Amsterdam
I started my PhD in December 2012, supervised by dr. Martijn Egas. My research focuses on the plant-eating arthropod Tetranychus evansi - a spider mite. This spider mite species originated in South America but has recently become an invasive species in many parts of the world. The rapid spread of this species is of concern for agriculture, because it likes to eat many commercially grown crops, such as tomato, potato, aubergine and pepper.
One reason why T. evansi can so easily infest these plants is that it can suppress their defense. The exact mechanism behind this is unknown, but it causes the infested plants to be very edible compared to other plants. Upon infestation, the spider mites quickly multiply, and cover the plant with dense webbing. Within 2-3 weeks the plant dies, and the mites disperse to find new host plants.
Suppression of plant defense is not new for science, but the extent to which T. evansi can suppress plant defense is unprecedented. Why is T. evansi so keen on suppressing plant defense? What evolutionary forces have driven this species to become such an aggressive suppressor? In my research I aim to find answers to these questions.
A.J. (Bram) Knegt MS
Population Biology - Institute for Biodiversity and Ecosystem Dynamics
University of Amsterdam
Science Park 904
1098 XH Amsterdam
a.j.knegt (at) uva.nl
- Knegt, B., Potter, T., Pearson, N. A., Sato, Y., Staudacher, H., Schimmel, B. C. J., ... Egas, M. (2017). Detection of genetic incompatibilities in non-model systems using simple genetic markers: hybrid breakdown in the haplodiploid spider mite Tetranychus evansi. Heredity, 118(4), 311-321. DOI: 10.1038/hdy.2016.103 [details]
- Becking, L. E., de Leeuw, C. A., Knegt, B., Maas, D. L., de Voogd, N. J., Abdunnur, ... Peijnenburg, K. T. C. A. (2016). Highly divergent mussel lineages in isolated Indonesian marine lakes. PeerJ, 4, [e2496]. DOI: 10.7717/peerj.2496 [details]
- Knegt, B., Jansa, J., Franken, O., Engelmoer, D. J. P., Werner, G. D. A., Bücking, H., & Kiers, E. T. (2016). Host plant quality mediates competition between arbuscular mycorrhizal fungi. Fungal Ecology, 20, 233-240. DOI: 10.1016/j.funeco.2014.09.011 [details]
- Knegt, B., Alba, J. M., Ataide, L. M. S., Barbosa, T. A., Bernardo, A. M. G., Chafi, R., ... Egas, M. (2017). Meta-analysis reveals intraspecific variation in herbivores for plant-mediated interactions. Poster session presented at Gordon Research Conference "Plant - Herbivore Interactions", Ventura, CA, USA, United States.