Isolation and characterization of the insecticidal compounds in Anacardium Occidentale (cashew nut) shell liquid against the rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae)

In the present study, insecticidal compounds in cashew nut shell liquid against Sitophilus oryzae were isolated and characterized. Bioassay guided isolation led to the isolation and identification of three major cardanol derivatives, (Z)-3-(8- pentadecenyl)phenol (1), (8Z,11Z)-3-(8,11-pentadecadienyl)phenol (2) and (8Z,11Z,14Z)-3-(8,11,14-pentadecatrienyl)phenol (3). Of the three compounds, compound 3 with a yield of 36.55 mg in the 1 g equivalent of extract, showed the highest insecticidal activity with LC50 value 60.36 mg/mL (95% CL = 64.52 – 126.41) against adult S. oryzae. These results suggest that cashew nut shell liquid has insecticidal potential and can be used in the management stored product beetles especially S. oryzae.