A CO2-free synthetic host-odor blend evokes trapping-related behavior in triatomines, vectors of Chagas disease

GUIDOBALDI F; GUERENSTEIN PG

Huerta Grande - COR

Congreso; 2nd Meeting of the Latin American Association for Chemical Ecology; 2012

Asociacion Latinoamericana de Ecologia Quimica, CICYTTP-CONICET, Fac. Agronomia-UBA

Chagas disease is a serious health problem in Latin America. The vectors of thedisease, which transmit the protozoan Trypanosoma cruzi, are triatomine insects.Vector control is the most effective method to prevent Chagas disease [1]. Vectormanagement is mainly accomplished by insecticide spraying of infested houses.However, this is not ideal considering that the insects develop resistance to theinsecticides, and that these chemicals could affect people living in treatedhouses. The use of lured trap devices is a sustainable and an environmentallyfriendlymethod for vector control [2]. Thus, it is possible to monitor and controlthe bugs without generating any resistance or toxic effect for humans.Using two of the most important Chagas vectors, Rhodnius prolixus and Triatomainfestans, we test potential odor attractants in a dual-choice trap olfactometer. Inthis olfactometer, the insects have to be activated, attracted and captured in orderto obtain a response to an odor source. We tested a blend of synthetic odors thatdid not include CO2, a compound that is either expensive or unpractical to use inthe field. The synthetic blend, consisting of L(+)-lactic acid, hexanoic acid andammonia, was assayed using live mouse odor as positive control. The positivecontrol, 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 tosignificantly trap the insects would imply that it is a strong attractant. This is thefirst time a CO2-free synthetic host odor blend is able to capture a significantnumber of triatomines in a trap-olfactometer.[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 ofTriatominae bugs, in: Takken, W. and Knols, B. (Eds.), Ecology and Control ofVector- Borne Diseases Volume II: Olfaction in Vector-Host Interactions.Wageningen University Press, pp. 309-325.