How do mosquitoes find their “victims”?

In a study published last week, a team of biologists identified the relevant morphological and biochemical structures that combine to give the Aedes aegypti mosquito its infrared detector and ability to find the best place to bite. Among other things, these pesky creatures We rely on the carbon dioxide we exhale, smells, primitive vision, the temperature of our skin and the moisture in our bodies.However, each of these signals has its own characteristics and limitations.

In addition to causing itchy bites, mosquitoes can also carry diseases like dengue fever, yellow fever, and Zika. With that in mind, scientists are constantly looking for ways to combat them. But to find a weak spot, you need to understand each stage of the mosquito’s life cycle, and what functions it uses to find its target.

Mosquitoes do not have perfect vision, so relying on a combination of sensesTheir senses also protect them from danger by responding to visual and mechanical indicators that they are facing a threat while feeding (i.e. an open hand ready to attack).

Mosquitoes can sense heat from about 10 centimeters away from human skin. They can sense the heat directly when they touch our skin. But the most interesting thing is what they respond to the most. thermal infrared radiation.

How mosquitoes “see” your hand depending on how you’re dressed / Photo: DeBeaubien and Chandel

The researchers measured how female mosquitoes, responsible for all bites in the experiment, sought out their targets at two points; both were exposed to human odors and carbon dioxide at the same concentrations we breathe. But one of the points was also exposed to thermal infrared radiation from a source whose temperature was equal to the temperature of the skin. This doubled the mosquitoes’ homing activity. The mosquitoes’ sensitivity to heat increased significantly with the active infrared source.

No single signal alone will stimulate host-seeking activity. Infrared only occurs in the context of other signals, such as high carbon dioxide and human odor.
– says biologist and senior author of the study, Craig Montell.

What to do with it?

The team believes that Loose clothing may be the most effective protection against mosquitoesbecause it leaves more space between the skin and clothing to disperse thermal infrared radiation than tight-fitting clothing, making it harder for insects to find their target.

However, this discovery has no other practical application yet, since a person will still radiate heat into the surrounding space and breathe out carbon dioxide. Theoretically, this discovery could help us find ways to repel mosquitoes in the future, which could reduce the spread of disease.