évaluation des pouvoir insecticide des extraits aqueux de deux Euphorbiaceae sahariennes dans la région de Ghardaia

Abstract

The study carried out focuses on the insecticidal effect of leaf extracts from two Euphorbiaceae including Euphorbia guyoniana (Boiss. & Reut) and Euphorbia retusa (Forssk) collected in Oued Sebseb, northern Sahara in eastern Algeria. The phyto-chemical screening of the aqueous extracts of the two plants shows a remarkable richness in active ingredients (alkaloids, coumarins, reducing compounds, free quinones, tannins and terpenoids). The concentrated extract (crude) of Euphorbia guyoniana, generate a rate of mortality of 100% after 28h, therefore for Euphorbia retusa generate a mortality rate of 90% in the insectes of Tribolium confusum after 64h hours of exposure. The lethal dose estimate shows that the leaf extract of "Euphorbia guyoniana" is more toxic than the leaf extract of the species "Euphorbia retusa"; the marked doses are successively of the order of 0.21 mg / ml; 0.62 mg / ml; 0.13mg / ml and 0.40mg / ml respectively.