Feromona de marcaje de frutos de Anastrepha ludens (Diptera: Tephritidae): extraccion y evaluacion.

espagnol; castillan. De heces de la mosca mexicana de la fruta, Anastrepha ludens (Loew) se obtuvieron extractos metanolicos de la feromena marcadora de frutos huespedes y se aplicaron sobre futis artificiales y naturales para determinar su efecto sobre la oviposicion de A. ludens. Los bioensayos en laboratorio indicaron que la aplicacion de los extractis sobre frutos artificiales reducen significativamente (P= 0.05) el numero de oviposturas y de huevecillos de A. ludens, con respecto a los testigos. Cuando el extracto se aplico a naranjas, toronjas, guayabas y mangos, los frutos presentaron menor numero de larvas con relacion a los testigos y las diferencias fueron significativas (P= 0.05). El corrimiento del extracto sobre una placa se cromatografia de capa fina, mostro un total de 14 bandas; la aplicacion de la fraccion 13, con un Rf cercano a 1, sobre frutos artificiales, causo un efecto similar al observado durante la aplicacion del extracto crudo. Los resultados sugieren que las hembras de A. ludens pueden discriminar a los huespedes marcados con el extracto de la feromona, independientemente del tipo de fruto y de la procedencia del insecto.

anglais. Methanolic extracts of the fruit marking pheromone were obtained from feaces of the Mexican fruit fly Anastrepha ludens (Loew) applied on artificial and natural fruits to determine their effects on female oviposition. Extract concentrations were 0.25 and 0.046 g of feaces/ml of methanol for the laboratory bioassays and field experiments, respectively. The laboratory bioassays indicate that the application of extracts on the artificial fruits reduces significatively (P= 0.05) the egg laying, in comparison with the control. When the extract was applied to oranges, pomelos, guavas and mangoes, they had a significatively less number of larvae in relation to the control (P= 0.05). The running of the extract on a thin layer chromatography plate, showed a total of 14 bands; the application of the fraction 13 (R sub (f) on artificial fruits caused similar effects to those observed during the application of the crude extract. Regardless of the kind of fruit and the origin of the insect, the A. ludens females were able to discriminate the hosts marked with the pheromone extract.