Getting bit by a mosquito is more than just an annoyingly itchy bump; it can also lead to life-threatening diseases like dengue fever, malaria, West Nile virus, and more. As such, many areas that are severely affected by these diseases have focused their efforts on controlling the population of mosquitos. New research has pinpointed exactly how mosquitos are able to detect human beings, which could lead to better repellant techniques. This study comes from lead author Genevieve M. Tauxe from the University of California at Riverside and was published in the Dec. 5 issue of Cell.
Scientists have known for a while that mosquitos are drawn to carbon dioxide, which signals to them that there must be a respirating host nearby. When it finally gets close enough to attack, it targets specific areas on the body, likely based on smell. Mosquitos are more drawn to the smelly areas on a human’s body, like the feet and ankles. Unfortunately, the details of why this happens have not been very well known, until now.
The research team discovered that receptors on the mosquito’s maxillary pulp, the same region that allows them to detect the CO2, is also responsible for gathering other desirable scents as well. For a long time, scientists assumed that the two methods of locating an individual must have come from two different places. Understanding exactly how mosquitos find a target is critical to finding better ways to disrupt the process and mask a human’s presence in order to prevent disease.
Testing on the mosquito that spreads dengue fever involved disabling the neurons that detect carbon dioxide (cpA). Then, when the mosquito was exposed to the desirable smell of a stinky foot, it showed little interest. This confirmed that fully functional cpA is necessary for mosquitos to detect a host.
Next, the team tried to identify compounds that repel mosquitos or lure them away. After trying almost half a million different things, they found over 100 prime candidates that are inexpensive, natural, and nontoxic. As an added bonus, they smell like good things like berries and mint, instead of the traditional off-putting odors of conventional mosquito repellants that rely on carbon dioxide detection.
This new information can help develop new, more efficient methods of mosquito population control by luring mosquitos away from large groups of people and repelling them if they get too close. Considering millions of people have been affected by mosquito-borne diseases, this research could help save lives all over the world.