%0 Journal Article
%T Evaluation of the toxic activity of the pyrethroid insecticides deltamethrin and lambdacyhalothrin in two Panamanian field populations of Rhodnius pallescens (Hem赤ptera: Reduviidae) Evaluaci車n de la actividad t車xica de los insecticidas piretroides deltametrina y lambdacihalotrina en dos poblaciones de campo de Rhodnius pallescens (Hem赤ptera: Reduviidae) de Panam芍
%A Lorenzo C芍ceres
%A Jos谷 R. Rovira
%A Jos谷 Calzada
%A Azael Saldaˋa
%J Biom谷dica
%D 2011
%I Instituto Nacional de Salud
%X Introduction. Systematic evaluation of the susceptibility of disease vectors to insecticides permits the detection of the development of insecticide resistance over time. This is necessary to evaluate the effectiveness of control methods and to plan management strategies of the resistance.Objective. The baseline susceptibility was determined for I and V instar nymphs of Rhodnius pallescens to the active ingredients of the insecticides deltamethrin and lambdacyhalothrin.Materials and methods. The bioassays were applied to two field populations of R. pallescens collected in Chilibre and Cerro Cama, Panam芍. A standard protocol for topical application was adapted from that developed for Rhodnius prolixus. Bioassays were performed using topical applications on the dorsal abdominal surface, with volumes of 0.1 米l and 0.5 米l acetone solution of insecticide for nymphs of stage I and V respectively, using 5 米l and 25 米l Hamilton microsyringes with a repeating dispenser. Ten nymphs were used for each insecticide concentration.Results. With the topical application of lambdacyhalothrin on first-instar nymphs from Chilibre and Cerro Cama, the LD50 values expressed in ng/insect were 0.13 and 0.11 respectively. In fifth-instar nymphs the LD50 values were 1.71 and 3.48, respectively. For deltamethrin, the topical application on first-instar nymphs resulted in LD50 values of 0.02 and 0.02, and in fifth-instar nymphs the LD50 values were 2.11 and 1.55, respectively.Conclusions. In I and V instar nymphs from the two R. pallescens populations, resistance factor values demonstrated no significant difference in the toxic effects of the two insecticides and indicated that the R. pallescens populations were susceptible them. Introducci車n. La evaluaci車n de la sensibilidad de las poblaciones de Rhodnius pallescens permite detectar y vigilar los grados de resistencia en el transcurso del tiempo, con el fin de evaluar los efectos de las estrategias de control y manejo de la resistencia. Objetivo. Determinar la l赤nea base de sensibilidad de los principios activos deltametrina y lambdacihalotrina en ninfas de estadios I y V, en dos poblaciones de campo de R. pallescens. Materiales y m谷todos. Los bioensayos se realizaron tomando como referencia el protocolo estandarizado de aplicaci車n t車pica para R. prolixus y adaptado para R. pallescens. Resultados. Con la aplicaci車n t車pica del insecticida lambdacihalotrina en ninfas de estadio I en R. pallescens (Chilibre) y R. pallescens (Cerro Cama), los valores de la dosis letal 50 (DL50) expresados en nanogramos por insecto fueron de DL50=0,129
%K Rhodnius
%K insecticidas/toxicidad
%K resistencia a los insecticidas
%K enfermedad de Chagas
%K Panam芍
%U http://www.revistabiomedica.org/index.php/biomedica/article/view/330