Repellency of Eucalyptol and DEET Against Triatoma infestans, a Chagas Disease Vector: A Proof-of-Concept Study Under a Human Odor Background

Abstract

Simple Summary Triatomines, also known as kissing bugs, are blood-feeding insects that transmit Chagas disease. Control of Triatoma infestans, one of the main vector species, relies largely on pyrethroid insecticides. However, insecticide resistance and environmental concerns highlight the need for additional strategies to protect people. Here, we evaluated the volatile repellent activity of eucalyptol, carvacrol, carvone, and DEET under conditions that prevented direct contact between the insects and the compounds, and in the presence of human odors, providing a realistic assessment of their potential for human protection. Moreover, eucalyptol and DEET were tested at very low doses. All four compounds strongly repelled the insects at the highest dose tested. Eucalyptol and DEET remained highly effective at lower doses and strongly reduced biting. Overall, our findings are a proof-of-concept suggesting that eucalyptol and DEET are highly effective repellents and bite inhibitors against T. infestans. These results highlight eucalyptol as a promising compound that could complement DEET in safer and more sustainable strategies for protecting people from Chagas disease.