Speaker
Description
Female Aedes aegypti mosquitoes employ remarkably robust, seemingly "unbreakable" host-seeking behavior to detect and bite humans, making them highly effective vectors for dangerous arboviruses including dengue, Zika, and chikungunya. While insect repellents containing DEET and picaridin effectively disrupt this persistent attraction and prevent bites, their precise mechanisms of action remain unclear. DEET has been demonstrated to possess both volatile and contact modes of repellency, but despite various hypotheses explaining how repellents function, the inability to disentangle their multimodal effects has hindered our understanding of the underlying sensory mechanisms.
To address this challenge, we developed the mosquito HOSTel—a novel behavioral chamber enabling precise spatiotemporal control of stimulus delivery with independent manipulation of contact and non-contact delivery modes. Coupling this system with a custom-made, open source, deep learning-based tracking platform capable of monitoring large numbers of individual mosquitoes without identity loss, we demonstrate that picaridin functions primarily as a contact-based repellent with orco-independent action and spatially circumscribed effects.
To investigate the sensory basis of these behavioral differences, we are employing in vivo calcium imaging of mosquito leg sensory neurons to examine how picaridin and DEET may engage different chemosensory pathways to disrupt host-seeking behavior. This integrated approach combining behavioral quantification with physiological investigation aims to elucidate how these leading repellents break one of nature's most resilient and epidemiologically significant behaviors.
