My research involves molecular and evolutionary ecology of the interactions between phytophagous insects, their host plants and their natural enemies.
As a model, I study the interaction between the flea beetle, Phyllotreta nemorum, its cruciferous host plants (especially Barbarea vulgaris) and a natural enemy (the parasitoid Aneuclis brevicauda). I aim to understand the evolution of the interactions between these organisms by studying the genetic basis of adaptations and the factors that influence the distribution of these adaptations.
P. nemorum is polymorphic for the presence of resistance genes, which enable the beetles to use B. vulgaris as a host plant. B. vulgaris is unsuitable as host plant for P. nemorum individuals in which the resistance genes are not expressed. The distribution of the resistance genes can be influenced by selection and migration, where ecological factors, such as host plant phenology, abundance of host plant species, and parasitism may play a role.
In my work I try to find the relationship between the geographical- and host plant associated distribution of resistance and population structure, indicated by neutral markers. I also study the selective forces acting on resistance, such as trade-offs associated with the presence of resistance genes, host plant dependent parasitism of P. nemorum, temporal variation in defence of B. vulgaris, availability of the various host plant species, and the interactions between these factors. Eventually the results of this work will contribute to a better understanding of the processes influencing biodiversity.
Apart from the importance of knowledge about processes connected to biodiversity for management of ecosystems, the genetic basis of the resistance of P. nemorum for defence of B. vulgaris resembles the genetic basis of insecticide resistance in insects. Therefore, the research on this model will certainly yield valuable insights in processes influencing the spread of resistance against insecticides. Moreover, P. nemorum (as well as closely related species) itself is a pest, and it is important to understand its host plant use to be able to develop environmentally benign control methods.