Dispersal is a fundamental concept to modern biology in that it can affect speciation, biodiversity, and species extinction. However, there is a minimal link between theoretical models of dispersal in the literature and empirical data. Furthermore, science can always benefit from the link between fundamental and applied biology. Therefore, my PhD project will focus on the spider mite Tetranychus urticae, a major agricultural pest affecting over 900 plant species world wide. This species can be selected on to form lines based on host specialization and on dispersal ability. From these lines, theoretical models on dispersal can be tested through experimental evolution. After the lines are created, the genetics of dispersal can also be studied with the knowledge of at least three candidate genes. This work will all be done at the University of Montpellier 2 in France under co-supervision from Caroline Nieberding and Isabelle Olivieri who has expertise in modelling and in genetics. Finally, I hope to use this knowledge of dispersal in T. urticae to improve integrated pest management (IPM) strategies in industrial agriculture. This work will be done at the University of Louvain-la-Neuve where I have access to large greenhouses and will be in contact with agricultural experts.  There are three main objectives of my work: Artificial selection, experimental evolution, and model testing
While theoretical models predict that with an increase in host specialization comes a decrease in dispersal ability, these models have yet to be tested. Therefore, I would like to create selection lines of T. urticae based on host specialization and dispersal. Once these lines are created, I will perform experiments to test the fitness of these lines in spatio-temporal stochastic environments and hopefully provide a link between theoretical models and empirical data. Genetic basis of dispersal
I intend to have several lines of T. urticae which differ in dispersal ability (high and low dispersal). There are several candidate genes in the literature that are related to physiological processes that affect dispersal, such as metabolism and foraging behaviour. I plan to study the genetic basis of dispersal by testing the role of these candidate genes in producing the low and high phenotypes. Using the same high and low lines, I will also try to find new genes that may be responsible for dispersal. Biological control
T. urticae is a major pest in agricultural greenhouses and so any information that can help control this species is valuable. Information about how these mites disperse in a greenhouse could help growers anticipate invasion and also provide information about how the set-up of their plants might affect dispersal throughout their greenhouse. I intend to study the dispersal of naturally invading mite populations into heterogeneous greenhouses. I will then use the high and low dispersal selection lines to examine how dispersal affects the ability of two major predators to control mite populations. This project benefits from the expertise of external collaborators: - Dr. D. Bonte, Ghent university (Belgium)
- Dr. T. Van Leeuwen, Ghent univ. (Belgium)
- Dr. S. Magalhaes, Lisbon univ. (Portugal)
- Prof. I. Olivieri, Montpellier univ. (France)