Scientists have discovered that adding this simple product to certain insecticides increases their effectiveness against mosquitoes.
Summer is approaching and, with it, its horde of mosquitoes which are preparing to bite millions of French people at the first heat. In addition to the traditional mosquito, in recent years there has been the threat of the tiger mosquito, now reported and present in the vast majority of France. On a global scale, the threat is even greater: mosquitoes are considered the deadliest animals in the world, transmitting devastating diseases such as malaria, dengue fever and yellow fever. Faced with this scourge, the fight against mosquitoes is a public health issue and it is therefore not surprising that researchers around the world are working on solutions.
Unfortunately, current insecticide solutions, based on harsh synthetic chemicals, lose effectiveness over time. The cause: the growing resistance of mosquito populations to several classes of pesticides. “Some populations can survive exposure to 10 times the dose of insecticide that kills susceptible mosquitoes,” warns Colince Kamdem, assistant professor of biological sciences at the University of Texas at El Paso, interviewed by Newsweek magazine.
To try to counter this worrying phenomenon, researchers have turned to neonicotinoids. This special class of insecticides has shown promise in laboratory testing and field trials. However, not all mosquito species are equally susceptible. This is why Professor Kamdem’s team looked for a simple and inexpensive way to boost the power of these molecules.
Their discovery is as surprising as it is exciting: an ordinary liquid soap, like we find in our bathrooms, combined with neonicotinoids can multiply their effectiveness by 10! “Based on our knowledge of the chemical properties of the surfactants in liquid soap, these substances likely solubilize some insecticides and reduce the thickness of the insect’s cuticle, allowing more pesticides to reach their target in the tissues “, explains Professor Kamdem.
In the study, published on November 17, 2023 in the journal PLOS Neglected Tropical Diseases, the three brands of soap tested increased mosquito mortality by 30 to 100% compared to the use of insecticides alone. A spectacular result which opens up new perspectives in the fight against mosquitoes and the diseases they transmit.
Although the precise mechanisms of this association between simple soap and neonicotinoids still remain to be elucidated, researchers are confident. They now hope to develop an effective soap-insecticide formulation that is inexpensive and safe for humans, which could be deployed on a massive scale, particularly in Africa.
“We do not yet know whether such a composition will adhere to supports such as mosquito nets, but the challenge is as promising as it is exciting,” rejoices Professor Kamdem. If the results are confirmed, this chance discovery could well revolutionize the fight against mosquitoes and save millions of lives.
