How Mosquitoes Are Drawn to Human Skin and Breath

Brennan O'Toole

Core Biology H/D Even

Current Event #2-Ms. Davies

Pittalwala, Iqbal. "How Mosquitoes Are Drawn to Human Skin and Breath." UCR Today. N.p., 5 Dec. 2013. Web. 19 Dec. 2013.

“How Mosquitoes Are Drawn to Human Skin and Breath”

In recent research published in the journal Cell, scientists pinpointed the part of the mosquito that makes them attracted to humans. Originally, these scientists from the University of California, Riverside knew that female mosquitoes are initially attracted to the exhale of CO₂ by humans, but that once they get near enough to the humans, these mosquitoes change their path and travel to an area of the body exposed by skin. However, the scientists conducting this research experiment, namely Anandasankar Ray, wanted to understand why mosquitoes change their path and how they detect certain skin odors. The researchers hoped that they would be able to block these odor sensors in mosquitoes or reduce the attractiveness of human odor, effectively diminishing the presence of mosquito bites on humans. The scientists discovered that the receptor neurons in the maxillary palp of the mosquito, known as cpA, are responsible for mosquito attraction to both CO₂ and skin odors, including smelly socks, worn clothes, and bedding. This was a significant and new finding because, previously, scientists had been focusing on the complex mosquito antennae rather than the simple maxillary palp organs. The fact that cpA is a receptor for both CO₂ and skin odors is additionally ground-breaking because it offers understanding of this insect’s human attraction and preference, along with identifying this receptor as a target to be used to disrupt mosquito attraction behavior. The UC Riverside researchers then proceeded to chemically disrupt the activity of the cpA in the Aedes aegypti mosquito, and found that the mosquito’s attraction to foot odor in an experimental wind tunnel was significantly reduced, supporting the findings of the researchers. Next, the research team began testing chemical compounds that were a desirable scent to humans, such as mint and raspberry, safe, and inexpensive, as they would be used to either inhibit or further activate the cpA receptors in mosquitoes. They decided that ethyl pyruvate, a fruity-scented compound already approved as a flavor agent in food, could be used to reduce a mosquito’s attraction to human skin by inhibiting the cpA. Conversely, cyclopentanone, a minty-smelling fragrance agent, could be used to activate the cpA receptor and lure mosquitoes into a specific area away from humans.

The isolation of the skin and CO₂ receptors in the maxillary palp and the discovery of two compounds that could both inhibit and activate cpA will have positive effects on many areas of the world. Female mosquitoes have the capability of transmitting deadly diseases, such as malaria, dengue fever, the West Nile virus, and filariasis to human populations, especially in South America, the Caribbean, Asia, and Africa. Compounds that block the cpA, such as ethyl pyruvate, will mask humans from mosquitoes and the harmful diseases they carry, and can be applied safely to human skin. On the other hand, compounds like cyclopentanone, which activates cpA, can be used to lure mosquitoes into traps and protect larger areas and a greater number of people at a time. This research was especially significant for people living in poorer countries because it offers more affordable solutions, in the form of compounds, rather than the former expensive solution of burning fuel to generate CO₂ as a mosquito trap.

This article was able to concisely express the large significance that the discovery of the cpA receptor as a receptor for both CO₂ and human skin odor will have on the human population, specifically for those living in continents where mosquitoes transmit deadly diseases. As a reader, this article, although it contained many scientific terms, was very easy to follow with the way that it went into thorough explanation on why the location of the dual CO₂ and skin receptor will have large effects on future preventative action against mosquitoes. This article was also enjoyable to read because it included both the discovery of the cpA receptor, along with the two chemical compounds that were chosen as a result of this discovery to combat mosquitoes. Finally, this article was engaging because it addressed a very relatable issue, the presence of mosquitoes and the diseases they carry, which affects the global human population. If there was one thing to critique about this article, it would probably be the lack of explanation on how the researchers discovered that the cpA receptor was a dual-receptor for CO₂ and skin odor, and how they located it within the maxillary palp. Other than that, the article succeeded in presenting a biological discovery that will potentially improve the lives of over 500 million people in an easily understood manner.

https://ucrtoday.ucr.edu/19377