DEET is the most widely used and effective commercially available repellent. It is able to act on a diverse group of arthropod pests (e.g. mosquitoes and ticks) and provides an adequate level of protection from bites. Despite its general acceptance, the mode of action of DEET remains elusive, with evidence pointing to several molecular targets and pathways, which can change based on concentration, species, and route of exposure. Ticks possess a unique sensory structure (Haller's organ) that allows them to detect hosts in the environment through spatial volatile detection and it is thought that DEET interferes with this process. What remains to be fully explored is the role of the Haller's organ in the repellency effect of DEET, and the possible molecular targets of the repellent within the tissue. Using transcriptomics approaches, our study investigates the changes of gene expression in ticks exposed to DEET both with and without their Haller's organ.
