"The migratory strategy is an evolutionary response to heterogeneity in either time or space that is common in animals, including many insects. The dispersal of myriads of insects has relevant economic consequences with examples including the pollination of agricultural systems, the association with pest outbreaks and the spread of infectious diseases. The case of the butterfly Vanessa cardui is an ideal model to study population dynamics of insect migrations because the species is distributed worldwide, it does not perform diapause and is extremely polyphagous. While this cosmopolitan butterfly represents what is potentially the widest distributional range of any migratory species, its migratory behavior is poorly known. In this project I propose to perform a comprehensive study of V. cardui genetic population structure, including an analysis of its worldwide migratory routes, the genetic causes and consequences of migration, aspects of the physiology of its migratory habits and possible outcomes of future climatic changes. This multidisciplinary project will involve the use of new technological and theoretical advances in next-generation sequencing, genomic analysis and coalescent-based phylogeography. The exceptional amount of specimens and data that will be assembled will represent a precious resource for future research on population genetics and ecology. Given the biological traits of this remarkable animal, results will have a strong impact and will attract the attention of researchers from different disciplines, and V. cardui will emerge as a model organism for the study of worldwide migrations."