Synthetic host odors could be used to manipulate both the host-seeking and oviposition behavior of triatomines

GUIDOBALDI F; GUERENSTEIN PG

Simposio; 3er congreso de la Asoc. Latinoamericana de Ecologia Quimica (ALAEQ); 2014

Ver tambien documento adjunto Chagas disease is a serious health problem in Latin America. The vectors of this disease, which transmit the protozoan Trypanosoma cruzi, are triatomine insects. Vector control is the most effective method to prevent Chagas disease [1]. Vector management is mainly accomplished by insecticide spraying of infested houses. However, this is not ideal considering that the insects develop resistance to the insecticides, and that these chemicals could affect people living in sprayed houses. The use of lured trap devices is a sustainable and an environmentally-friendly method for vector control [2]. Thus, it would be possible to monitor and control the bugs without generating any resistance or toxic effect for humans. For this, powerful odor attractants have to be developed. For this, we carried out experiments on the olfactory basis of the host-seeking and oviposition behaviors of triatomines. Using two of the most important Chagas vectors, Rhodnius prolixus and Triatoma infestans, we tested potential host odor attractants in a dual-choice trap olfactometer, which is a very challenging device. In this olfactometer, the insects have to be captured in a trap in order to score a response to an odor source. We tested several blends of synthetic odors that did not include CO2, a compound that is either expensive or unpractical to use in the field. Synthetic blends, consisting of L-(+)-lactic acid, valeric acid and ammonium hydroxide (all odors detected by triatomines), were made using different volumes of the solutions of each of the three components in individual LDPS (low density polyethylene sheets), and were assayed using live mouse odor as positive control. The positive control, as well as the synthetic blends tested, evoked significant attraction (capture) both, in R. prolixus and T. infestans. The fact that the blends were able to significantly trap the insects would imply that they are strong attractants. The different blends tested varied in their capture performance. In the case of R. prolixus the best blend evoked 81% capture in a single night (this represents a significant capture respect to a negative control with no odor, G-test, p