Mosquitoes, despite being tiny, have sensory powers that enable it to sniff out potential targets including humans and animals, a new study has found. The study, published by researchers in the laboratory of Michael Dickinson, the Esther M. and Abe M. Zarem Professor of Bioengineering, shows that mosquitoes have three sensors – olfactory, visual, and thermal – that detect where exactly your delicious blood is. Researchers found that mosquitoes are attracted by odour of carbon dioxide (CO2) gas that is exhaled naturally by humans and other animals.
Riffell and his colleagues hope these nerve cell recording experiments will help them understand how insects integrate and interpret different signals from their environment and use this information to make decisions.
So, researchers concluded that mosquitoes have full control over their senses, which they “gate” when on a hunting mission.
During the same experiment, the researchers also injected background air with a low concentration of Carbon dioxide.
Experiments by other scientists implied that the mosquito sense of smell might activate other senses in the quest for a host.
A team of biologists from the University of Washington and the California Institute of Technology has discovered the method mosquitoes use to find us.
Riffell believes the mosquitoes went to the black dot – a high-contrast spot in an otherwise featureless environment – thinking that a warm-blooded host was nearby.
In the study, mosquitoes were put in a wind tunnel that was plain and empty, except for a black dot on the floor to serve as a visual stimulus.
Researchers released hungry, mated female mosquitoes into a wind tunnel to find out how and when the mosquito uses each of its sensors.
The blood-drinking femme fatales in question are not, perhaps unfortunately, Kate Beckinsale style heavily beweaponed lady vampires clad in a variety of form-fitting outfits and very likely having got a bit wet by falling in a pool, getting caught out in the rain etc. No, these are just mosquitoes: but in all fairness mosquitoes are probably more of an issue for the human race than sexy vampires on any given day so it’s hard to fault the priorities of the investigating boffins. “That means that they smell the CO2, then they leave the plume, and several seconds later they continue flying toward this little object”.
When the team also released heat and water vapor around the dark spot in their experiments, mosquitoes seemed even more attracted to it. But contrary to the mosquitoes’ visual attraction to objects, the preference for warmth was not dependent on the presence of Carbon dioxide. Even in this case, however, mosquitoes could still locate you by tracking the heat signature of your body. “Only when the mosquito gets closer does it detect an object’s thermal signature”, van Breugel said. But then if you were in a group of people, and somebody else wasn’t taking those precautions, then a mosquito would follow their Carbon dioxide plume. “The independent and iterative nature of the sensory-motor reflexes renders mosquitoes’ host seeking strategy annoyingly robust”.