In today’s Academic Minute, Dr. Anandasankar Ray of the University of California Riverside explains how mosquitoes are able to track us down from great distances.
Anandasankar Ray is an associate professor of entomology at the University of California Riverside. His lab seeks to understand the molecular, neuronal and physiological basis of insect chemoreception and behavior, specifically as they relate to food-seeking behaviors. He holds a Ph.D. from Yale University.
Dr. Anandasankar Ray - How Mosquitoes Smell
The tiny female mosquito is one of the deadliest creatures on this planet. Nearly half the world’s population is at risk from diseases they transmit, and nearly a million people die every year from malaria, dengue, west Nile fever and filariasis. The female mosquito feeds on blood for nutrients to produce eggs. When it bites an infected person the disease can be transmitted to others it feeds on later in life.
A hungry mosquito smells us using sensitive sensors on the surface of the antennae and the maxillary palps. From a distance it first detects carbon dioxide plumes from our exhaled breath and uses them to navigate towards us. As the mosquito comes closer, it starts smelling odors from exposed skin and is attracted even more.
The carbon dioxide molecules are known to activate special receptor proteins in neurons of the maxillary palps. However, receptors that cause attraction to skin odor remained elusive till now. A recent study in my lab has identified skin-odor sensing neurons in the mosquito. And to our surprise, the same receptor that detects carbon dioxide also detects odors from our skin.
This dual detector of skin and carbon dioxide presents a key target to alter mosquito behavior. Using a computational method we predicted hundreds of odors that could artificially inhibit or activate this receptor. From them we identified several that were natural, pleasant smelling and affordable. An inhibitory odorant that smells fruity could block detection of skin odors and mask a human arm from mosquitoes. Conversely an activating odorant that smells minty could lure mosquitoes into a trap.
Odors like these present a new generation of affordable strategies to reduce diseases transmitted by mosquitoes.