My main interests are trophic interactions between plants and insects and in particular how the spatial structure of the habitat influences these interactions. During my PhD I have studied the effects of habitat fragmentation on the tri-trophic system of the plant Silene latifolia, the herbivore moth Hadena bicruris, and its parasitoids. For that research I have studied many subpopulations of S. latifolia with different degrees of isolation and size in a large metapopulation structure in the Netherlands. One of the findings was that in small patches of the plant the level of herbivory is higher, not because, as initially expected, parasitoids are more often absent, but due to a relative increase in the number of eggs deposited by the herbivore. Furthermore I have studied in detail the life history characteristics of the parasitoids that attack the herbivore.
My post-doc project at the DEE has several goals. First, with microsattelite markers I want to study the effects that habitat fragmentation has on the genetic structure of the plant populations. Do small and/or isolated populations of Silene latifolia have a higher level of inbreeding? How related are the different subpopulations within the metapopulation structure?
Does the genetic structure influence the level of herbviory? For this work I will do fieldwork and collect leaf samples in the metapopulation in the Netherlands.
Secondly, I am interested in the effects that population size may have on the selection process on phenological patterns. The timing of flowering is an important factor determining the vulnerability of the developing seed capsules to herbivory of Hadena. One of the potential ways to reduce the risk per seed capsule is to flower simultaneously and saturate the herbivores. However this would only work in large plant populations. In small populations extending the flowering time could be a better strategy to reduce the risk of herbivory.
But there is likely to be a trade-off between the avoidance of the herbivore and the succesfull pollination and development of seeds. I will study the effects that the timing of flowering and the level of synchrony have on the development and risk of herbivory of individual seed capsules in experimental plant patches with different levels of synchrony and size. I expect that in large plant patches selection pressure will favour increased synchrony for phenology whereas in small patches we expect asynchrony to be more favourable for successful seed development. Also, I will investigate whether the level of synchrony within the plant affects its vulnerability to herbivory.
Other possible projects could be: To study the effect of aging of the flower on the trade-off between attracting pollinators and reducing attractiveness to the herbivore, or to compare the Swiss parasitoid complex on Hadena with the Dutch one.