During the last years, headlines about the advance of tropical infectious diseases, which are transmitted by mosquitos, become more frequent. Some of these mosquitos are classified as invasive species in Europe. The World Health Organization (WHO) and the European Center for Disease Prevention and Control (ECDC) are enhancing the observation of the geographical spread of these species. Especially the Asian tiger mosquito and the Yellow fever mosquito are in focus. In Germany the vector competency of domestic mosquito species is investigated.