Evaluation of biocidal activity of four Lamiaceae leaves on the black bean aphid Aphis fabae Scopoli, 1763 (Homoptera: Aphididae)

Abstract

The objective of our work was the valorisation of four aromatic plants growing spontaneously in Kabylia (Algeria) by the evaluation of their insecticidal activity against the black bean aphid Aphis fabae Scopoli, 1763. These are oregano, thyme, rosemary and lavender. The plants were subjected to a phytochemical analysis to determine their secondary metabolites composition. The results obtained showed that the four extracts are toxic to A. fabae and can significantly reduce its populations. LD50s of 7.76 %; 8.91 %; 9.72 % and 12.88 % were recorded for extracts of oregano, rosemary, thyme and lavender respectively. In addition, the phytochemical screening shows the presence of flavonoids, tannins, saponins and polyphenols. The polyphenols extraction indicates that the oregano extract is the richest with a polyphenol content of 218.73 (± 0.22) µg GAE ml-1. This substance has significant biocidal power.