Uso de cuatro extractos organicos para el control del pulgon verde (Myzus persicae Sulz)

Extracts of leaves and stems of Neurolaena lobata; leaves, stems and fruits of Momordica charantia, wood of Quassia amara and seeds of Annona muricata, were tested regarding their effectiveness for control of green peach aphid (Myzus persicae). In a first stage, groups of 10 individuals of M. persicae were placed inside petri dishes together with a small and slight piece of synthetic cloth soaked with either substance extracted. Several concentrations were used. After two hours; more than 50% of the individuals had been killed in every petri dish, which allowed all extracts to pass on to the second stage. The second stage consisted of two experiments. The first one was done in spring at a greenhouse day temperature of 10°C, using only the first three substances, each of them diluted 1:100. The second one was conducted in Summer at about 25°C with the four substances. Distilled water acted as a control in both experiments. Tobacco plants (Nicotiana tabacum) infested with M. persicae were sprayed with the solutions and survivors counted 24 and 72 hours later. In the first experiment Q amara and M. charantia had 78% and 77% effectiveness respectively, which were statiscally (P< 0.05) higher than that of N. lobata (63%). In the second experiment, because of the warmer weather, they improved their performance, specially N. lobata (98%). This and A. muricata were found statistically (P< 0.05) higher than the others. Se evaluó el efecto de hojas y tallos de Neurolaena lobata; hojas, tallos y frutos de Momordica charantia; madera de Quassia amara y semillas de Annona muricata en el áfido verde Myzus persicae. El trabajo consistió de dos etapas. En la primera se aplicaron los extractos a pedazos pequeños de tela sintética, los que se colocaron dentro de platos Petri, junto con diez áfidos por plato; se emplearon concentraciones 1:100 y 1:1.000. Después de dos horas, todos los extractos eliminaron más del 50% de la población, lo que permitió que todos ellos pasaran a la segunda etapa, la cual consistió de dos experimentos.El primer experimento se llevó a cabo en primavera, a 10°C, aproximadamente, con los tres primeros extractos, y el segundo en verano, aproximadamente a 25°C y con los cuatro extractos. En ambos se infestaron plantas de tabaco con M. persicae y se aplicaron los extractos. A las 24 y 72 horas se efectuaron los conteos del número de insectos presentes. En el primer experimento Q. amara y M. charantia presentaron similar efectividad (78-77%) y sup