Natural products were screened for their insect repellent activity, and carrot seed essential oil gave very high activity in biting repellent/deterrent bioassays. Analysis of the oil revealed the presence of 47 compounds, mainly mono- and sesqui-terpenes. The sesquiterpene, carotol, constituted more than 75% w/w of the oil. In the initial screening, the essential oil gave high biting deterrent activity and high repellent activity comparable to DEET against both Aedes aegypti and Anophies quadrimaculatus species of mosquitoes. The active fraction mainly comprises pure carotol. The essential oil and the pure compound have a potential to be developed and used as effective repellent against mosquitoes.
