Actividad antialimentaria e insecticida de un extracto de hojas senescentes de Melia azedarach (Meliaceae)

Antifeedant and insecticide activity of an extract from senes- cent leaves of Melia azedarach (Meliaceae). In the course of screening for novel naturally occurring insecticides from plants, the activity of a senescent (yellow) leaf extract of Melia azedarach L. (Meliaceae) was investigated. An- tifeedant effects were tested on five Lepidoptera and four Coleoptera species, in laboratory choice tests. Further effects on insect feeding and survival we- re studied in no-choice tests with larvae and adults of Epilachna paenulata Germar (Coleoptera: Coccinellidae). In the choice tests, M. azedarach ye- llow leaf extract strongly deterred feeding in eight out of the nine species considered. Larvae and adults of E. paenulata which received only extract- treated food suffered higher mortality rates; larvae did not reach the pupal stage. Insects receiving extract-treated food ate less and larvae had lower body weight than their control counterparts, suggesting that the observed in- crease in mortality might be related to the strong antifeedant activity of the extract. The effects were significantly related to extract concentration.