A better natural mosquito repellent

Abstract

Found in lemon eucalyptus, p -menthane-3,8-diol (PMD) is the only natural chemical on the US Centers for Disease Control and Prevention’s list of recommended mosquito repellents. Scientists have now discovered that one form of PMD may repel certain types of mosquitoes nearly as well as the benchmark synthetic mosquito repellent, DEET, while being significantly less toxic to people ( J. Agric. Food Chem. 2021, DOI: 10.1021/acs.jafc.1c03897 ). DEET is commonly used to fend off mosquitoes, but it can irritate the skin and be neurotoxic . Many natural alternatives are less toxic but evaporate quickly, limiting their effectiveness. In contrast, PMD lasts longer. In nature, PMD can be found as a mix of four diastereomers, so organic chemist Marc Lemaire of Claude Bernard University Lyon and colleagues in France and Madagascar tested how well each of the diastereomers repelled the Aedes albopictus mosquito . On human skin, one diastereomer, (1 R