Scientists capture in detail, for the first time, how a malarial mosquito bites beneath the skin

How the experiment was conducted

Malarial mosquitoes need blood in order to lay eggs. As Kun.uz notes, most previous studies focused on how insects find humans by smell or heat, while the biting process itself remained comparatively little studied. In the new work, scientists attached extremely thin electrical wires to the sensory organs of mosquitoes of the species Anopheles coluzzii. This method made it possible to record, in real time, the slightest changes in force as the insect's proboscis penetrates under human skin. The electrical signals were matched with high-speed video recordings.

Five phases of the bite and a comparison of species

As a result, the researchers identified five phases of the bite: piercing the skin, searching for a blood vessel, drawing up blood, withdrawing the proboscis, and fully completing the bite. According to their observations, when piercing the skin, the mosquito uses sensitive organs on its legs and around its mouth, and once blood-sucking begins, the insect becomes completely still. The results were published in the journal Science Advances. The scientists also compared the behavior of the malarial mosquito with that of the Aedes aegypti mosquito, which carries dengue fever: it turned out that the malarial mosquito finds a vessel under the skin on average 17 seconds faster. At the same time, the overall duration of the bite proved to be almost identical in both species — about two and a half minutes. Given that the evolutionary paths of these species diverged roughly 150 million years ago, the researchers suggested that both species may have independently arrived at an equally effective feeding method.

The role of the olfactory gene and the significance of the work

In separate experiments, the scientists switched off the activity of the gene IR76b, which is linked to mosquitoes' sense of smell. After that, the insects almost completely lost the ability to purposefully search for a blood vessel, and the probability of successful blood-feeding dropped sharply. In the authors' view, understanding how a mosquito moves under the skin and how it uses its sensory organs could in the future help create more effective means of protection against the infections it transmits. Editorial comment: the work is important primarily for regions where malaria remains a serious problem — if the findings are confirmed, the vessel-searching mechanisms and the sensory pathways involved, including the gene IR76b, could become targets for new repellents or other protective measures. At the same time, the authors themselves emphasize that this concerns possible future applications: no specific protective products based on these data have yet been created.