The migratory locust is one of the most devastating insects of the world, with swarms emptying huge areas of crops and pasture. The locust also has a very different olfactory architecture as compared to other insects, with more than a thousand micro glomeruli in the antennal lobe, branched axons of olfactory sensory neurons and unorthodox morphology among both projection and local interneurons. In a concerted effort, using state-of-the-art methodology, we set out to investigate the system from beginning to end; from olfactory receptors to behavior. By introducing locust olfactory receptors into the Drosophila empty neuron system we could gain insight into the specificity of single receptors. To have a relevant stimulus spectrum we identified molecules emanating from all life stages of the locust and of preferred and not-preferred food souces. In this way we could deorphanize most of the ca. 100 receptors. Among the receptors we discovered one that responded specifically to the pheromone phenylacetonitrile (PAN). In behavioral experiments we revealed the effect of this compound. By using CRISPR-cas9 tecnhnique we could then knock out the PAN receptor and show that the behavioral traits were abolished. In ongoing experiments we are now using genome editing to introduce calcium dynamics indicators in olfactory receptor neurons, allowing us to observe antennal lobe processing of relevant odor information. This project is a collaborative venture between Max Planck and the Chinese Academy of Science.