Abstract The analysis by GC/MS of samples of essential oils obtained from aerial parts of Hedeoma mandoniana allowed the identification of 58 components. The main components were pulegone (37â46%), 1,8-cineole (10â14%), linalool (7â12%) and 1-octen-3-yl acetate (7â12%). We investigated the efficacy of these oils against the Chagas' insect disease vectors (Triatoma infestans Klug or Rhodnius neglectus Lent) bugs by topical application. Two samples showed a moderate activity (33.3% of mortality) on Rhodnius neglectus exemplars.