“Study Identifies Chemicals in Body Odor That Attract Mosquitoes”

2023.05.27 Sat posted at 12:50 JST

（ＣＮＮ） The presence of mosquitoes that plagues people on hot and humid summer nights. The results of a study that looked at what components of body odor attract mosquitoes have recently been published in an academic journal.

By pumping various human body odors into a laboratory the size of a skating rink and observing mosquito behavior, the researchers identified the chemicals that attracted mosquitoes. The research was published today in the scientific journal Current Biology.

Mosquitoes are members of the fly family and mostly feed on the nectar of flowers, but females that are about to lay eggs suck blood in search of a source of protein.

If you get stung, you will usually only experience redness, swelling and itching. However, mosquitoes can also carry parasites and viruses that carry infectious diseases such as malaria.

Malaria kills more than 600,000 people a year worldwide, mostly children under the age of five and pregnant women, according to author Conor McMeniman of Johns Hopkins University.

So McMeniman and his colleagues set out to find out how malaria-carrying mosquitoes find humans.

The research team focused on the gambier anopheles, which lives in sub-Saharan Africa, and investigated the ecology of mosquitoes in collaboration with a research institute in Zambia. We investigated the body odors that mosquitoes like, their ability to trace odors from a distance of 20 meters, and their behavior during the period from 10:00 pm to 2:00 am, when they are most active.

The experimental facility measures 20 meters in length and width, and six tents were set up around it. Absorbent pads were placed inside the facility to simulate a sleeping person, warming them and releasing carbon dioxide.

Hundreds of mosquitoes were placed in the facility, exposed to the breath and body odor of the subjects, and their movements observed with an infrared camera (the mosquitoes used in the experiment were not infected with malaria and could not approach the subjects). did not).

They found that some people attracted a lot of mosquitoes and others didn’t, and chemical analysis of the air in the tents revealed the substances responsible for the smells that attract mosquitoes.

The components of the air that most attracted mosquitoes were carboxylic acids such as butyric acid. Butyric acid is a component found in strong-smelling cheeses such as Limburger. Such carboxylic acids are made by bacteria on human skin and tend to go unnoticed by humans.

While mosquitoes are attracted to carboxylic acids, they seem to dislike eucalyptol, a chemical found in plants. The researchers speculated that the high-concentration eucalyptol sample was related to the diet of one of the participants.

Researchers point out that it is very interesting that this study found a correlation between chemicals contained in various human body odors and the behavior of mosquitoes attracted to the smell. It is hoped that the technology will be useful in developing insect repellents to keep mosquitoes at bay and in combating malaria in endemic areas.