BIO-INSECTICIDAL EFFECT OF POLYPHENOL EXTRACTS OF ANVILLEA RADIATA AGAINST CEREAL APHID RHOPALOSIPHUM PADI

To reduce the abusive apply of artificial organic pesticides with discernment, biodegradable bio-pesticides origin from plants were used as an alternative phytosanitary method against crop pests. This experimentation allowed testing in vitro the bio-insecticidal activity of Anvillea radiata Coss and Dur (Asteraceae), endemic plant from the southeastern Algeria, against the cereal aphid Rhopalosiphum padi (Linnaeus, 1758). Three concentrations were tested (D1= 5mg/ml, D2= 2.5mg/ml and D3= 1.25mg/ml) with the butanolic and chloroformic extracts. The results showed a mortality rate of R. padi varying significantly by treatment and concentration according to the tested substances. The quantitative analysis of the two extracts shows that the crude butanolic extract is rich in polyphenols (348.935±7.456 µg EAG/mg MS) compared to the crude chloroformic extract (56.754±0.982 µg EAG/mg MS). Samely to the insecticidal effect tested, the concentration of 5 mg/ml presented an important insecticidal activity with the butanolic extract (62%) higher than the chloroformic extract (26%). Also, the lethal doses (LC50) of the crude butanolic extract were estimated by 23.07 mg/ml, 6.71 mg/ml and 5.70 mg/ml respectively after 24, 48 and 72hours of the treatment.