A recent small-scale study suggests that citrus-scented products may not repel mosquitoes, as commonly believed, while coconut-scented products may offer that benefit.
Mosquitoes, those pesky blood-sucking insects, have long been a source of annoyance and discomfort. Recent research has delved into the fascinating realm of scents and soaps and their impact on mosquito attraction.
In this analysis, published in the journal iScience, scientists explored the intricate interplay between human body odors and scented soaps and their appeal to mosquitoes.
Lead study author Clement Vinauger, an assistant professor of biochemistry at Virginia Tech specializing in mosquito genetics, aptly described the research question as deceptively simple with an intricately layered answer.
The investigation debunked the notion that a single soap could repel mosquitoes unequivocally; instead, the key factor appears to lie in the nuanced interplay of scents in the chemical amalgamation of soaps and individual body odor.
Among the noteworthy findings, coconut emerged as a surprising repellent for mosquitoes, while citrusy scents, often associated with repelling these insects, paradoxically attracted them. Understanding this apparent contradiction required delving deeper into the biology of mosquito feeding habits.
Female mosquitoes, the exclusive seekers of blood meals necessary for their egg development, normally nourish themselves on sweet-scented flowers. When humans apply perfumed products to their skin, they unwittingly blur the boundary between human and floral scents.
Mosquitoes perceive this convergence and associate our skin with a resource that encompasses both human and plant elements. This phenomenon partially explains why certain scents can either attract or repel mosquitoes, depending on their chemical composition.
The unique scent emanating from an individual is the result of over 350 chemicals, some produced by our bodies and others by the bacteria residing on and within us. While everyone shares these chemicals, their ratios differ, rendering some individuals more attractive to mosquitoes than others.
Ali Afify, who works as an assistant professor of biology at Drexel University, emphasized that factors like pregnancy, illness, physical activity, and even consumables, such as beer, can alter these chemical ratios and subsequently impact mosquito attraction.
Additionally, perfumes, soaps, and lotions wield their influence on the delicate equilibrium of scents, making humans either more or less attractive to mosquitoes.
To uncover the chemicals that sway mosquito attraction, the researchers enlisted four volunteers in a series of experiments. Each volunteer washed one forearm with one of four different soap brands: Dial, Dove, Native, and Simple Truth. The other forearm remained untouched.
Afterward, nylon sleeves were worn on both arms for one hour. This method was repeated with each of the four soaps. Following the hour, the researchers collected the odor-soaked sleeves, placing each in a cup within a mesh cage containing Aedes aegypti mosquitoes, the species prevalent in the southern portion of the United States.
The results astonished the scientific community. Although all four soaps contained limonene, a compound found in citrus known for its mosquito-repellent properties, three of the soaps actually made individuals more attractive to these insects.
Furthermore, the odor samples taken from the washed arms exhibited elevated levels of terpene, a compound commonly found in essential oils, including the scent of cannabis. Terpene tends to be repellent to mosquitoes, but it did not seem to deter them in this study, suggesting that what they were detecting was much more complicated.
The study did not find conclusive evidence of any substance or odor that would repel all mosquitoes, but it does suggest that further research is warranted.
