Studies on the spatiotemporal occurence of mosquitoe-borne pathogens in German mosquitoes (Culicidae: Diptera) and on the microbiome of the invasive Asian tiger mosquito (Aedes albopictus) and its displacement potential towards native species

To promptly register future outbreaks of mosquito-borne diseases of humans and animals and to be able to take prophylactic measures if necessary, the examination of German mosquitoes for pathogens is essential. The vector competence of a mosquito can be influenced by, among other things, microorganisms that are part of its microbiome. Therefore, studies of the microbiome of native and invasive mosquito species, which may serve as vectors of a variety of pathogens relevant to humans and animals, is essential. Among these vectors, the mosquito species Ae. albopictus, a neozoic species in Germany, plays a dominant role. This species has been present in Germany since 2007, but it is unclear whether it is an invasive species according to the EU Environmental and Nature Protection Act. The classification of Ae. albopictus as an invasive species could enable control measures for this species to be enforced by law, thereby preventing the spread of this highly invasive vector species. Therefore, it is particularly crucial to investigate different fields of mosquito biology to develop an integrated concept for the protection of the human population. On the one hand, this requires knowledge about the spread of mosquito-borne pathogens. Knowing which pathogens circulate in German mosquitoes and which areas of Germany are hostspots of circulation would make it possible to take prophylactic and timely measures to reduce the risk of transmission to humans and animals. New, efficient, and practicable control measures for mosquitoes must be developed to prevent the establishment of new vector species in Germany and to be able to regulate German mosquito populations if necessary. However, to be able to implement control measures against invasive mosquito species including vector species, their distribution within Germany and their influence on the German mosquito fauna must be investigated. Only when this knowledge is available legal and uniform control measures can be taken. Since these interdisciplinary studies on various aspects of the German mosquito fauna are critical for a holistic knowledge of mosquitoes in Germany, three different aspects of the mosquito fauna are dealt with in this dissertation. These three aspects overlap and thus provide a coherent picture of the German mosquito fauna. This study aimed to investigate whether Ae. albopictus is an invasive species in Germany using three taxa from the Cx. pipiens complex in a competition experiment. In addition, this study examined the microbiota of Ae. albopictus from German populations and screened mosquitoes that were captured in Germany for human and veterinary viruses. On the one side, these studies are meant to monitor the spread of mosquito-borne pathogens in Germany to enable timely control measures to be adopted. On the other side, the microorganisms registered in Ae. albopictus may help to modify the vector competence of Ae. albopictus or be used to develop new vector control measures in the future.