Scientific study shows bathing soap could scare off or attract mosquito bites

According to a study funded by the USDA National Institute of Food and Agriculture and published in iScience Journal (published May 10, 2023), Scientists showed that soaps affect mosquito-host selection, with some soaps increasing attractiveness of the host and some soap scaring off mosquitos.

According to the researchers, plants emit wide arrays of chemicals including terpenes, esters, alcohols, aldehydes and other chemicals which are detectable by mosquitos. They further said the use of soap is not just for addition of scents to our body, but it also replaces chemicals and washes away other host chemicals. Altered concentrations of aldehydes have been linked to the modulation of mosquito attraction to humans.

Four soaps chosen based on previous knowledge of their popularity and fragrance were used for the study. The presence of several known chemicals that alter mosquito’s attractiveness according to the authors were also used as a selection criterion. For each of the four soaps, the scientists tested four volunteers. The soap application resulted in increases in the relative amounts of terpenes, and even ketones/esters in the host profile. The researchers believe that terpenes, and ketones (esters) can serve as mosquito kairomones.

Whereas soaps with flowery scents increased mosquitos’ attractiveness to the host, soaps designated as natural evoked least attraction of the mosquitos to the host.

It is not clear if the effect observed by the researcher in this study with Aedes Aegypti (a yellow fever casing mosquito) would trigger similar response(s) in other mosquito species. However, this study is thrilling, in that, it may lead to changes in behavioral habits with respect to use of soap and could also lead to improvement in chemical combinations for insect repellants.

Reference: Soap application alters mosquito-host interactions. VanderGiessen M et al., 10 May 2023, iScience. https://doi.org/10.1016/j.isci.2023.106667