Khaberni - A new study revealed that mosquitoes do not chase each other, but are all attracted to the same invisible signals that lead them directly to humans.
The study clarifies that mosquitoes individually respond to the same signals (dark color + carbon dioxide), a discovery that could improve mosquito traps and reduce deaths from diseases transmitted through their bites.
After observing hundreds of mosquitoes and analyzing about 20 million data points, researchers from the Georgia Institute of Technology and the Massachusetts Institute of Technology developed a mathematical model explaining how female mosquitoes determine the location of humans and approach them to feed on their blood.
This work provides the first detailed visual representation of mosquito flight behavior and offers measurable insights that can improve control methods and trapping.
Mosquitoes are not just a nuisance, but they transmit diseases such as malaria, yellow fever, and Zika, which collectively cause more than 700,000 deaths annually. The team also created an interactive website that allows users to explore mosquito movement and behavior.
The researchers used three-dimensional infrared cameras to monitor the response of mosquitoes to visual signals and carbon dioxide gas. They then placed a person inside a sealed chamber, changed his clothing colors, and recorded how mosquitoes moved around him.
The study focused on females of Aedes aegypti (yellow fever mosquito), which are found in the southeastern USA, California, and many other parts of the world.
The data indicate that mosquitoes do not congregate by following each other. Instead, each insect independently interacts with the same environmental signals, leading them to reach the same location at approximately the same time.
This is similar, according to Professor David Hu from the Georgia Institute of Technology, to “a busy bar where customers are attracted to the same drinks, music, and atmosphere, not because they followed each other. Mosquitoes are attracted to the signals and happen to arrive at the same point that others have reached”.
The researchers conducted three experiments to test the attractiveness of different visual targets, with and without carbon dioxide, and came to the following conclusions:
. The first experiment: A black object without carbon dioxide: In this case, mosquitoes were not attracted to the black object unless they were already flying toward it by chance. When they reached it, they did not stay long and soon left the area without attempting to feed.
. The second experiment: A white object with carbon dioxide: When a white object was placed and carbon dioxide gas was released, mosquitoes were able to locate the source, but only if it was sufficiently near. As they approached, they paused for moments as if "taking a second look" before they gathered around the object.
. The third experiment: A black object with both carbon dioxide together: This combination was the strongest attraction. With the presence of the black object and carbon dioxide gas together, mosquitoes gathered in large numbers, stayed in the area longer, and actually attempted to feed, confirming that the combination of the visual signal (dark color) and the chemical signal (carbon dioxide) creates a very strong attraction for mosquitoes.
Christopher Zuo, the researcher who conducted the study, said: “Previous studies have shown that visual signals and carbon dioxide attract mosquitoes, but we didn’t know how they integrate them to decide where to fly. They are like little robots; we just had to figure out their rules”.
After determining the importance of static visual signals, Zuo tested the behavior on himself inside the mosquito chamber. He wore different outfits (all black, all white, and a mixture), and stood with his arms extended, while cameras recorded the flight paths.
Analysis of the data at the Massachusetts Institute of Technology showed that mosquitoes behaved as if Zuo was just another object. The largest gatherings formed around his head and shoulders (areas this species tends to target). He wore long-sleeve clothes with a head cover, and said he was not bitten much.
