Our study was carried out on the private farm of Mr Chebaani in Sidi Okba in the wilaya of Biskra (Algeria), to test the toxicity of a bio-pesticide of the aqueous extract of Ruta graveolens (Rutaceae), on the larvae and adults of the white scale (Parlatoria blanchardi Targ., 1868, Homoptera, Diaspididae) of the date palm. We sprayed three different concentrations (10, 30 and 50 g / l) of the aqueous extract of the bio-pesticide on the feet of date palm, and to determine the different chemical constituents of the bio-pesticide we carried out a Liquid Chromatography Mass Spectrometry (LC-MS). The study of the effect of the aqueous extract showed that the concentration 50 g/l, gave good results on the larvae and the adults of the white scale, with mortality rates of 85.33% and 64.33 %, respectively. The results also showed that the lethal concentration (LC50%) after 24 hours in the larvae is 3.91 g/l and in adults is 214.2 g/l. LC-MS analysis allowed the identification of 30 components, the main ones are: anethole (15.77 ppm), gardenin B (5.58 ppm), p-coumaroyl glycolic acid (5.17 ppm), 2,3-dihydroxy-1- guaiacylpropanone (5.12 ppm), hesperidin (4.8 ppm), and 3-sinapoyl quinic acid (4.49 ppm).
Author(s): Chebaani Hana, Tarai Nacer, Touiker Samira, Souilah Nabila, Raul Bonal