For approximately 226 million years, mosquitoes have inhabited our planet. As plant pollinators, flower nectar serves as their primary food source. However, to produce eggs that will properly hatch, females have to consume protein and iron, components conveniently found in blood. It is a result of this disposition that viruses such as dengue, yellow fever, and Zika have been able to mass spread amongst human populations. Considering the potential threat these organisms pose, efforts to neutralize them have yet to be successful. New research, however, may provide new insights.
Previous studies explored a variety of theories to explain the phenomenon behind the sensory cues (i.e., body heat and carbon dioxide exhalation) that may attract mosquitoes, but many lacked a scientific basis. A recent study, conducted by Dr. Maria Elena De Obaldia, explored how unique skin odors could be more “attractive” to mosquitoes due to the particular skin microbiota– the range of microorganisms, like bacteria, fungi, and viruses– they contain. This experiment required 64 participants to wear nylon stockings on their arms for six hours a day. Over a series of days, the stockings would absorb the individual’s skin odor. Afterward, Aedes aegypti (a genus of mosquitoes) would be released in a glass chamber containing two different stockings. Dr. Obaldia observed which stockings were frequently more attractive to the mosquitoes and found that those subjects produced higher levels of three carboxylic acids: pentadecanoic, heptadecanoic, and nonadecanoic, in addition to ten unidentified compounds in the same chemical class.
Mosquitoes serve as pollinators and food sources for other organisms.
Image Source: Joao Paulo Burini
These carboxylic acids are found in sebum, an oily substance produced by sebaceous glands situated on the surface of our skin. Sebum is believed to have beneficial effects, protecting the skin from sun damage and regulating body temperature. Skin bacteria interact with the sebum, generating different types of acids, which produces the characteristic “human smell.” It is theorized that this smell is also what attracts mosquitoes and makes certain people mosquito magnets. This trend has proven to remain stable over an extended period of time.
While there seems to be a correlation between carboxylic acids and mosquitoes, scientists have yet to determine the reasoning behind the relationship. Nonetheless, this newfound knowledge does provide a new perspective on mosquito and insect repellent, giving researchers a more specific concept to explore. There is still hope for us mosquito magnets out there.
Feature Image Source: Photoboyko
