Scientists at the Institute of Technology and University of Washington reported that they found how mosquitoes can detect their juicy and unsuspecting prey. According to the findings, the pesky insects first use their razor-sharp sense of smell to approach their victims, and then they plan their feast with help from other senses.
“Very little was known about what a host looks like to the mosquito and how a mosquito decides where to land and begin to feed,”
noted Jeff Riffell, a researcher from the University of Washington and co-author of the study.
Past studies had shown that the insect’s sense of smell may play a crucial role in finding food, but Riffel and his fellow researchers wanted to know precisely which of the senses is more important during hunting.
To accomplish that, the research team put several mosquitoes in wind tunnels located in an enclosed environment to prevent them from escaping. The wind tunnels helped scientists simulate the exact wind conditions that affect the insects when they fly around looking for prey.
The wind tunnels were built without special features, but had a dark spot on the floor. Researchers wanted to learn what role mosquitoes’ sense of smell played in their quest for a delicious meal. So, they released a plume of CO2 around the wind tunnel’s dark spot to see what happens. When the insects came into contact with the gas we humans exhale with each breath, they suddenly became very interested in the black dot.
Scientists noted that the gas may have stimulated the mosquitoes visually so they can go to the only distinctive feature in the wind tunnel in hope that there may be a warm-blooded host.
So, researchers concluded that mosquitoes have full control over their senses, which they “gate” when on a hunting mission. In other words, mosquitoes do not attack a potential host until they can smell it. Seemingly, the tiny animals can sense us from the odor of the carbon dioxide we exhale every few seconds.
According to the study, the insects can track various scents, but they only enter combat mode and employ their vision when they sense a particular one.
When the team also released heat and water vapor around the dark spot in their experiments, mosquitoes seemed even more attracted to it.
As a follow-up, the team plans to study more how scents shape up mosquitoes’ behavior. They believe that the animals can tell blood hosts apart only from their body odors. Riffell explained that CO2 is a signal that a warm-blooded host is around which a mosquito can sniff from a 30 foot distance.
Image Source: Animal-animal-animal (blog)