Viruses are among the most diverse and abundant microorganisms on earth and we find them infecting all living lifeforms. Some, and the most studied, cause disease and sometimes even death while for many of the viruses we don’t know the potential effect, good or bad, that they have on their different hosts. In my projects we focus on viruses that infect and are spread by different arthropod vectors. Among these are pathogenic arboviruses but also the viruses specific to the vector. In these studies we identify and genetically characterise viruses in for example mosquitoes and ticks from different parts of the world and also do biological characterisation by investigating how they interact with the vector. In another research direction viruses of diseased and healthy pigs are studied and also here we do both genetic and biological characterisation in order to understand the role of co-infections when it comes to disease development.