Keeping mosquitoes at bay is one of the great challenges of human beings, not because of how annoying they are in summer, but also because their bite can transmit potentially deadly diseases such as malaria. So much so that mosquitoes are considered the most lethal animals for humans. We knew that mosquitoes depend largely on their sense of smell to bite us, thanks to a new studywe now know that they are also guided by sight.
Smell, the key tool.
Precisely because of this mixture of nuisance and danger, mosquitoes have attracted the attention of researchers of all kinds, and this implies that we have some notion of what it is that attracts them and to what other stimuli they are indifferent.
Although it is not the only clue that these animals rely on, smell is key for mosquitoes when it comes to locating their prey. Carbon dioxide (CO2) is one of the chemicals that we release and that attract the attention of these insects. For humans it is an odorless gas, but the females of these species, who are the ones who sting, are capable of detecting it.
Jeffrey Riffel, one of the co-authors of the new study and a professor of biology at the University of Washington, account in the press release how he used to explain that there are three main clues that attract the attention of mosquitoes: “your breath, your sweat and the temperature of your skin”. The work that he has carried out together with other researchers introduces a new element: “the color red, which can not only be found in your clothes, but also in the skin of the whole world”.
Also the view is important.
Riffel and colleagues’ study found that the mosquitoes they conducted their experiment with (Aedes aegypti) tended to fly toward specific colors, such as red, orange, black, or cyan, while ignoring others, such as green, purple, blue, or blue. the target. The human skin color It has reddish tones, which explains the preference of these animals for these colors. In general, mosquitoes prefer colors in the “long” part of the visible spectrum, that is, colors with long waves versus those with shorter waves. The exception is the middle zone (green and cyan).
This phenomenon would not be altered by the level of skin pigmentation, since the reddish tone remains in all skinsRiffel explains, adding that “filtering these attractive colors into our skin, or wearing clothes that avoid these colors could be a different way to prevent mosquito bites.”
Aedes aegypti, one of the most dangerous.
The analysis was carried out with females of a specific species of mosquito, Temples of the Egyptians, one of the most interesting to researchers because it is responsible for the transmission of numerous diseases, including yellow fever, Zika or dengue. It is also a species that is specialized in humans, that is, it does not attack other animals.
How did they perform the experiment?
There are other details of how the study was conducted that may be helpful in interpreting its results. The researchers created small chambers into which the animals were introduced. They presented a combination of visual patterns (from points of a specific color to the back of a hand) and olfactory patterns (in this case the presence or absence of CO2).
The team observed that the presence of CO2 was decisive, in its absence the mosquitoes ignored visual stimuli regardless of color, while in the presence of CO2 they only attended to certain colors while ignoring the rest. To replicate the experiment using hands, the researchers used filters and gloves to visually alter it.
What can we conclude from this experiment?
Before changing the bottom of the wardrobe for white and green clothes you have to take some things into account. The first is that we still do not know exactly how mosquitoes weigh the stimuli they are guided by, let us remember that color and CO2 are not the only clues on which they are based. The researchers mention this need to deepen our knowledge of how mosquitoes navigate.
The team also notes that more research will be needed to determine whether these results hold true. other mosquito species, perhaps more annoying but less dangerous. The specialization in humans of this species makes it logical that these insects turn to tones similar to those of our skin, but it is not clear if more “opportunistic” species of mosquito have other preferences.
Finally, that its objective is our skin, not our clothes. In Spain, mosquitoes are especially annoying in summer, when the most popular t-shirts are short-sleeved. Let us wear the color of clothes that we wear, our arms and legs will continue to be a call to the banquet for the mosquitoes. This study gives us, yes, a new clue in the fight to reduce the impact of these annoying insects.
Image | Vladislav Balakshii