Healthy Living

Oddly enough, until recently it wasn't entirely clear why mosquito repellents protect our skin from mosquito bites. A team from John Hopkins University in the United States investigated what mechanisms are in place.

According to the research team, it was not immediately clear why mosquito protective agents repel the critters, as it is difficult to observe how the mosquito's sense of smell reacts to these types of products. The researchers were able to use sophisticated techniques (genetic tools) to visualize the neuronal response of all the mosquito's odor organs. Also that of the feelers, which are actually the 'nose' of the insect. The research was carried out on live mosquitoes (Anopheles coluzzii).

What did they determine?

Whether it's DEET, IR3535® or repellents based on picaridine (icaridine), it's not the substances in those products in themselves that keep the mosquitoes away. The repellent effect occurs because these substances mask the body smells. Basically, the volatile molecules of these synthetic products and the body odors mix, significantly reducing the response of the mosquito's smell system. When a mosquito's sense of smell detects a body odor, its neurons are strongly activated, but when a mosquito-repellent product is applied to that body, it does not. In this way, a human body becomes 'invisible' or actually 'oderless' to the mosquito. The combination of body odour with mosquito repellent product causes the olfactory system (sense of smell) of the mosquito to be activated five times less strongly. The research team adds that natural anti-mosquito products such as citronella or eugenol work in a different way. They cause a strong activation of a small group of neurons located in the antennae. The researchers assume that their repellent effect is due to the fact that mosquitoes do not like these odors.