A triatomine trapping-related behavior is induced by a CO2-free synthetic host odor blend

FABIO GUIDOBALDI; PABLO G. GUERENSTEIN

Huerta Grande

Congreso; 2° Meeting of the Latin American Association of chemical ecology; 2012

Asociación Latinoamericana de Ecología Química, ALAEQ

Chagas disease is a serious health problem in Latin America. The vectors of the 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 is possible to monitor and control the bugs without generating any resistance or toxic effect for humans. Using two of the most important Chagas vectors, Rhodnius prolixus and Triatoma infestans, we test potential odor attractants in a dual-choice trap olfactometer, which is a very challenging device. In this olfactometer, the insects have to be activated, attracted and captured in order to obtain a response to an odor source. We tested a blend of synthetic odors that did not include CO2, a compound that is either expensive or unpractical to use in the field. The synthetic blend, consisting of L(+)-lactic acid, hexanoic acid and ammonium, was assayed using live mouse odor as positive control. The positive control, as well as the synthetic blend, evoked significant activation and attraction (capture) in R. prolixus and T. infestans. The fact that the blend was able to significantly trap the insects would imply that it is a strong attractant. Nevertheless, the blend tested is less powerful than a live host, and therefore the blend performance should be improved. In any case, this is the first time a synthetic host odor blend is able to capture a statistically significant number of triatomines.   [1] WHO, 2010. Chagas disease (American trypanosomiasis). Fact sheet N°340. http://www.who.int/mediacentre/factsheets/fs340/en/index.html [2] Guerenstein, P.G., Lazzari, C.R., 2010. The role of olfaction in host seeking of Triatominae bugs, in: Takken, W. and Knols, B. (Eds.), Ecology and Control of Vector- Borne Diseases Volume II: Olfaction in Vector-Host Interactions. Wageningen University Press, pp. 309-325.   We thank Fundación Bunge y Born and Agencia Nacional de Promoción Científica y Tecnológica, Argentina, for funding this project through grants FBB28/10 and PICT-PRH-2009-43, respectively