A laboratory assessment on the effect of powder from Foeniculum vulgare and Eruca sativa against saw-toothed grain beetle Oryzaephilus surinamensis (L.)

Abstract

This study was conducted to determine the insecticidal activity of botanical powders from Fennel, Foeniculum vulgare Miller and Eurca sativa Miller against saw-toothed grain beetle Oryzaephilus surinamensis (L.). Plant powders were admixed with wheat grains at concentrations of 5.0, 10, 20, 40, 60, 80 and 100 g/kg. The mortality was determined after 24 and 48 h after treatment then the flasks were kept to get F1 progeny. Results showed that all tested concentrations for both F. vulgare and E. sativa exhibited high toxicity effects on O. surinamensis adults and the high toxicity rate was concentration and time dependent. On the basis of lethal toxicity (LC50) value fruit powder from F. vulgare were more toxic to O. surinamensis adults than seed powder from E. sativa at 24 and 48 hrs after treatment. Also, the fruit powder of F. vulgare caused a very strong F1 progeny population inhibition activity against O. surinamensis with the highest inhibition rate was counted from the wheat grain treated with 80 g/kg and 100g/kg for F. vulgare fruit powder and E. sativa seed powder, respectively. Moreover, these plant materials had no adverse effect in the germination percentage of wheat grains treatment. These results indicated that F. vulgare fruit powder and E. sativa seed powder could be applicable to the management of stored product insects to decrease ecologically detrimental effects of using insecticides.Key word: saw-toothed grain beetle, insecticidal activity, powder, Foeniculum vulgare, Eurca sativa.