pA striking commonality across species is the recurring presence of parallel olfactory systems, such as the main olfactory system, the vomeronasal system, the septal organ and the Grueneberg organ in mammals. Similarly, different subsystems are present in amphibians, fish and insects, suggesting that parallel systems have a highly adaptive value. We will use the honeybee Apis mellifera to study a species where two olfactory subsystems of about equal size have been found: the IACT and the mACT pathway. While their presence in Hymenoptera and their neuroanatomical segregation is established, we do not know the morphological details nor the functional relevance of this segregation. The honeybee is an excellent model system for olfactory research thanks to its highly developed olfactory system. There is a large body of already published research, and a wealth of paradigms to study olfactory behavior, including learning and memory with close to cognitive capacities. We will use neuroanatomy, immunohistochemistry and ultrastructural analyses, combine these with opto- and electrophysiological measurements, and analyze the behavioral role that parallel olfactory systems have in olfactory processing in the honeybee. We expect to improve our understanding of olfactory coding mechanisms in general, and of the significance of parallel pathways in sensory systems in particular.