Detection of metabolite content in local bitter white lupin seeds (Lupinus albus l.) and acaricidal and insecticidal effect of its seed extract

This study investigated the acaricidal and insecticidal effect of local lupin (Lupinus albus L. Fabaceae) seed extract against Tetranychus urticae Koch (Acari: Tetranychidae), Callosobruchus maculatus F. (Coleoptera: Chrysomelidae), Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae) and metabolite content of seeds. In tests for T. urticae leaf-disk bioassay was employed. Contrarily, two μL of the L. albus extract were topically applied using a micro-applicator on C. maculatus and P. interpunctella. In the assays of T. urticae and P. interpunctella, the concentrations of 0.78, 1.56, 3.12, 6.25, 12.5, 25% (w/w) of the plant extracts were used. Furthermore, the concentrations of 0.625, 1.25, 2.50, 5, 10% (w/w) were applied to C. maculatus. Mortality data was collected 24, 48 and 72 hours after application. In the results, L. albus extract was found to be quite effective to C. maculatus adults with LD50 of 7.26, 1.21 and 0.55% after 24, 48 and 72 hours, respectively. Moreover, lupin extract was effective to T. urticae adults with LC50 values of 4.03, 3.15 and 2.73% for the same durations. L. albus extract was showed low insecticidal effect against the larvae of P. interpunctella. In seeds metabolite content were detected, which contained 686.99 mg GAE / 100 mg total phenol, 22.06 mg QE / 100 mg total flavonoid, DPPH 26.04 mg TE / 100 g having antioxidant activity. The bitter taste of stem and seeds of the plant is due to their metabolite content which has a toxic effect. In conclusion, results indicated that lupin seed has a high secondary metabolites content and also its extract had the high toxic effect against T. urticae and C. maculatus.