Have you ever wondered how mosquitoes find you to bite you?
Well, a new Caltech (California Institute of Technology) study suggests that mosquitoes use a “triple threat” of sight, smell, and thermal cues in order to target humans.
In a study written in the journal Current Biology, and featured on EarthSky.org, researchers say when adult female mosquitoes need blood to feed their young, they search for a host, which is often a human. Mosquitoes are often attracted to the carbon dioxide odor that humans and other animals exhale. However, the study finds that mosquitoes also pick up on other cues that signal that a human is nearby. In fact, they use their vision to spot a host and their thermal senses to detect body heat.
Through a series of experiments, researchers hypothesize that from 10 to 50 meters away, a mosquito smells a host’s carbon dioxide plume. That’s anywhere from 33 to 164 feet away! As the pest flies closer, within 5 to 15 meters (16 to 49 feet), it begins to see the host. Then, guided by visual cues that draw the bug even closer, the mosquito can sense the host’s body heat. That happens less than a meter, or approximately 20 centimeters. Wow!
Here’s something else that will grab your attention! Michael Dickinson, professor of bioengineering at Caltech, says female mosquitoes search for their food in an “elegant” way. Dickinson says that female mosquitoes “only pay attention to visual features after they detect an odor that indicates the presence of a host nearby. This helps ensure that they don’t waste their time investigating false targets like rocks and vegetation.”
Cool, isn’t it?
So, is there any way to completely avoid mosquitoes? Well, experts say no. While repellents and candles can keep the pests away for a while, experts say mosquitoes have “evolved” to use their triple threat of visual, olfactory, and thermal cues to take a bite from their prey.
Sources: Caltech, EarthSky.org