Contribution à l’étude des activités répulsives et insecticides des extraits végétaux contre les ravageurs : Étude d’un cas

Abstract

This study aims to test the effect of two aqueous extracts of the leaves of the plant Salvia officinalis and Eucalyptus camaldulensis, on the adults of the black bean aphid (Aphis fabae) found on the bean (Vicia faba). Under laboratory conditions. We evaluated the insecticidal effect and toxicity of aqueous extracts on aphid mortalities by introducing bean leaflets into an extract and infecting it with 10 adults of the aphid. Then, a count was made of mortality rates after 3, 6, 12 and 24 H. In addition, we estimated the repellent effect of the aqueous extracts on bean aphids by placing them in the prime position between two leaflets, each treated with a different extract. In addition, we performed a phytochemical screening to detect the presence of Saponosides and tannins in the extracts studied. Through our study, the extract obtained from Eucalyptus camaldulensis at a concentration of 50% obtained by infusion was most effective with a mortality rate of 93% after 12H. These extracts give a remarkable repellent effect with a rate of 70% with a concentration of 50% on adults of aphids. On the other hand, extracts of Salvia officinalis record an acceptable result by the maceration method. Regarding the phytochemical screening, we observed that both plants contain saponosides and tannins.