Insecticidal and antifeedant properties of the medicinal plant Cinnamosma fragrans to control the mosquito vector Aedes aegypti

Research poster
Edna Ariel Alfaro Inocente
Pete Piermarini
Department of Entomology

Mosquitoes and the arboviruses they transmit are important concerns for global health. To date, mosquito control has been largely based on using chemical insecticides. However, overuse of chemicals with limited modes of action have led to resistance in mosquito vectors. Moreover, repeated use of conventional chemical pesticides leads to the accumulation of potentially harmful residues in the environment, and undesirable effects on non-target organisms, including beneficial insects and vertebrates. Thus, insecticides with novel modes of action are needed. Secondary metabolites in Madagascan plants of the genus Cinnamosma (Canellaceae) are commonly used in traditional medicines and known to elicit antifeedant and toxic effects in insect pests. In this project, we test the hypothesis that extracts of Cinnamosma sp. enriched in drimane sesquiterpenes are toxic and/or antifeedant to the yellow fever mosquito Aedes aegypti. We show that the bark and root extracts, which contain a higher abundance of drimane sesquiterpenes compared to leaves, were the most efficacious. Screening isolated compounds revealed cinnamodial to be the primary driver of adulticidal activity, whereas cinnamodial, polygodial, cinnafragrin A, and capsicodendrin contributed to the larvicidal activity. The antifeedant activity of the extracts was primarily contributed to cinnamodial, polygodial, and cinnamolide. Our results indicate that plant drimane sesquiterpenes provide valuable chemical platforms for developing insecticides and repellents to control mosquito vectors.