Odor emission from a trap for the vectors of Chagas disease depending of its physical attributes

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 vector's management is currently mainly accomplished by insecticide spraying of infested houses. However, this is not ideal considering that the insects could develop resistance to the insecticides, and that these chemicals could affect people living in sprayed houses. The use of trap devices to capture the insects could help monitor and control the bugs without generating any resistance or toxic effect for humans. One method to capture walking bugs is based on the use of adhesive tape. This method has been used to intercept bugs moving between different habitats [1]. Adhesive tape is also used as the trapping agent of the popular Noireau trap, baited with a mouse [2]. However, it is not known if, after being immobilized, the adults stuck become stressed and hence emit their alarm pheromone thus repelling larvae and adult conspecifics. If so, this could result in an overlooked reduction in the trapping performance of the device being used. To study this, we evaluated the effect of the presence of bugs stuck in adhesive tape on the capture performance of a trap lured with a mouse. Fifth-instar Triatoma infestans bugs starved for 1 month were tested, singly, in an experimental arena, overnight. Three experimental series were carried out: in series 1 the trap just contained a mouse, in series 2 the trap contained a mouse plus 10 T.infestans adults free to move inside it (but not allowed to contact the mouse), and in series 3 the trap contained a mouse plus 10 T. infestans adults stuck to adhesive tape (importantly, those bugs were stuck to the tape by their own, while walking free in an arena with small pieces of adhesive tape). Results show that the presence of insects (stuck or not) inside the lured trap do not affect capture (n=13, 12 and 11 for series 1, 2 and 3, respectively). Thus, the percentage of capture in all series was 100%. Our results suggest that the use of adhesive tape as a immobilization method in traps could be used without compromising attraction/trapping effectiveness.    [1] Abrahan L. B., Gorla D.E., Catalá S.S. 2011. Dispersal of Triatoma infestans and other Triatominae species in the arid Chaco of Argentina - Flying, walking or passive carriage? The importance of walking females. Mem. Inst. O. Cruz 106, 232-239.  [2] Noireau, F., Abad-Franch, F., Valente, S.A.S., Dias-Lima, A., Lopez, C.M., Cunha, V., Valente, V.C., Palomeque, F.S., Carvalho-Pinto, C.J., Sherlock, I., Aguilar, M., Steindel, M., Grisard, E.C. and Jurberg, J., 2002., Trapping Triatominae in sylvatic habitats. Mem. Inst. O. Cruz 97, 61-63.   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