Etude de l’activité insecticide des extraits de plante Ruta graveolens de la région de Ghardaïa

Abstract

Insect damage to grain and pulse stocks has been widely studied in Africa.The interest of this work is the biological control against two best known pests of stored cereals and legumes, Triboluim castaneum and Bruchus rufimanus using extracts from the aerial part (leaf, stem and flower) of the plant "Ruta graveolens" ofthe region of Ghardaïa and the evaluation of the insecticidal power of these extracts by contact treatment. The aerial part of the plant was subjected to extraction by maceration in two solvents: acetone and ethanol.The qualitative analysis carried out by phytochemical screening determined the presence of flavonoids, coumarins, saponosides and alkaloids.The quantitative analysis determined by a spectrophotometric assay showed the richness of the leaves by the phenolic compounds namely total phenols, flavonoids and tannins. The results under laboratory conditions showed that the tested extracts have a very strong insecticidal power.This efficacy is represented by calculated toxicological parameters, which in turn are LD50 and LD90.The sensitivity of adults was variable and even higher with increasing extract concentrations and with exposure time. In the context of biological control, the application of this insecticide product could be very effective against pests and for the protection of stocks of cereals and legumes.