Evolution of dispersal and host specialization in spider mites


Researchers: Caroline Nieberding (principal investigator), E. Bitume (PhD student)
External collaborator:
- Prof. I. Olivieri (Montpellier univ., France)
- Prof. Thiery Hance (UCL)

Dispersal, comprising any movement of individuals leading to gene flow, affects the distribution of genetic diversity among populations and is therefore involved in their genetic differentiation. Mathematical models have theoretically predicted how joint evolution of dispersal and of local adaptation, such as habitat specialization, can form new races and lead to reproductive isolation. Here we aim at testing the validity of these models predictions using artificial selection in a lab-designed controlled environment. We will also test the activity of several candidate genes for their role in dispersal, and if relevant estimate the number of loci involved in dispersal behavior. Third, we will evaluate the importance of dispersal in determining the spread of the two-spotter spider mite Tetranychus urticae Koch, model species of this research project, in greenhouses. As a pest of many cultivated plants, T. urticae is indeed an herbivorous mite of huge economical importance. We expect that a better understanding of the patterns of dispersal of mites in relation with habitat specialization may suggest ways of modifying the agroecosystem to reduce mite populations and concurrent use of pesticides.