Exploring unknown avenues of intra- and interspecies communication in Drosophila

The manuscripts within this dissertation aimed to investigate odor-mediated communication channels for the interactions of Drosophila flies with each other, other Drosophila species, and with microorganisms. Throughout the dissertation, I introduce the frass of adult Drosophila flies as a previously overseen intra- and possibly interspecies communication medium (manuscript I) and demonstrate the sensitivity of hardwired stereotypical behaviors, which are mediated by only a few chemosignals, to manipulation through harmful microbes (manuscript II). Furthermore, this dissertation highlights different factors that may be involved in Drosophila speciation events, such as niche partitioning (manuscript IV) and insect-microbe interactions (manuscript V). Finally, I worked on a previously described method that is used for the identification of ligand-receptor pairs of olfactory systems in mammals and tried to further establish this technique for the high-throughput identification of chemosensory receptor ligands in insects on the example of the vinegar fly D. melanogaster (manuscript III).