GUERENSTEIN Pablo Gustavo
Novel repellents for the blood-sucking insects Rhodnius prolixus and Triatoma infestans, vectors of Chagas disease
RAMÍREZ, MELANIE; ORTIZ, MARIO I.; GUERENSTEIN, PABLO; MOLINA, JORGE
PARASITES AND VECTORS
BIOMED CENTRAL LTD
Año: 2020 vol. 13
AbstractBackground: Studying the behavioral response of blood-sucking disease-vector insects to potentially repellent volatile compounds could shed light on the development of new control strategies. Volatiles released by human facial skin microbiota play different roles in the host-seeking behavior of triatomines. We assessed the repellency effect of such compounds of bacterial origin on Triatoma infestans and Rhodnius prolixus, two important vectors of Chagasdisease in Latin America.Methods: Using an exposure device, insects were presented to human odor alone (control) and in the presence ofthree individual test compounds (2-mercaptoethanol, dimethyl sulfide and 2-phenylethanol, the latter only tested inR. prolixus) and the gold-standard repellent NN-diethyl-3-methylbenzamide (DEET). We quantified the time the insectsspent in the proximity of the host and determined if any of the compounds evaluated affected the behavior of theinsects.Results: We found volatiles that significantly reduced the time spent in the proximity of the host. These were 2-phenylethanoland 2-mercaptoethanol for R. prolixus, and dimethyl sulfide and 2-mercaptoethanol for T. infestans. Such aneffect was also observed in both species when DEET was presented, although only at the higher doses tested.Conclusions: The new repellents modulated the behavior of two Chagas disease vectors belonging to two differenttriatomine tribes, and this was achieved using a dose up to three orders of magnitude lower than that needed toevoke the same effect with DEET. Future efforts in understanding the mechanism of action of repellent compoundssuch as 2-mercaptoethanol, as well as an assessment of their temporal and spatial repellent properties, could lead tothe development of novel control strategies for these insect vectors, refractory to DEET.