“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”,
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said UW biologist Jeff Riffell, co-author on the paper and one of three professors collaborating on these efforts.
The research team conducted experiments involving controlled environments like wind tunnels, where they could observe the pests’ behaviors.
The wind tunnels were built without special features, but had a dark spot on the floor.
For van Breugel, the results of their experiment were interesting findings about flies, so they suspected that mosquitoes would exhibit a similar behavior, Science World Report has learned.
The wind tunnels were mostly featureless, with the exception of a small dark dot on the floor.
What happens is pretty straightforward: the mosquito can smell a host’s carbon dioxide (CO2) from 10 to 50 meters away, which prompts it to fly closer.
He added that mosquitoes started to use their vision and their ability to distinguish the various types of body odor to differentiate whether their next meal is blood from a dog, a deer or a human, UPI reports. The introduction of carbon dioxide into the tunnel triggered the mosquitoes’ instinct to search visually for food, Riffel said.
“When we gave them the odor stimulus, all of the sudden they were attracted to this black dot”, said Riffell. “That is, we predicted that when the mosquitoes were exposed to CO2, which is an indicator of a nearby host, they would also spend a lot of time hovering near high-contrast objects, such as a black object on a neutral background”.
What this means is that the effect of mosquitoes’ olfactory systems is not dissimilar to our suffering. When the insects came into contact with the gas we humans exhale with each breath, they suddenly became very interested in the black dot.
If so, the experiments Riffell and his collaborators are doing now may prove this theory.
“In a previous experiment with fruit flies, we found that exposure to an attractive odor led the animals to be more attracted to visual features”, said Floris van Breugel, a postdoctoral scholar in Dickinson’s lab and first author of the study.
The final stage of guidance is heat, with the tiny airborne bloodsuckers appearing able to pick up typical body-heat signatures within a metre and use this to close in for a tasty draught of blood.
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.
Finally, mosquitoes are attracted by the heat of the human body, which researchers confirmed with a heated glass panel that otherwise blended in with its surroundings. This information could someday be used to help control mosquitoes, particularly the species that spread unsafe pathogens.
Study’s senior author Dr Michael Dickinson said that after sniffing Carbon dioxide plume, they only pay attention to visual cue.
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This research was funded by the National Institutes of Health.
