Abstract:
Laboratory experiments were conducted at the College of Agricultural Studies of Sudan University of Science and Technology to evaluate the lethal effect of damas Conocarpus lancifolius Engl,Castor Bean Ricinus communis L. , and korobi Nerium oleander against lesser grain borer Rhyzopertha dominica (Fabricius) . Three concentrations from each plant (5%, 10% and 15%) were used in this study. The results showed that all concentrations of the tested plants in various formulations gave significantly higher mortality percentage than the control after 24hrsof exposure.
The highest concentration (15%) of powder and 10% concentration of aqueous and ethanolic extract of damas used in this study, caused mortality of 43.3%, 46.7% and 55% respectively after 72 hrs of exposure. Meanwhile, the highest concentrations of castor bean leaves aqueous extract and ethanolic extract generated 60% and 66.7% of mortality respectively after 72 hrs of exposure, whereas, the same concentration of damas leaves ethanolic extract caused 56.7% mortality after 72 hrs of exposure.
The obtained results also revealed that the highest concentrations of nerium leaves powder, aqueous extract and ethanolic extract induced 46.7%, 55% and 58.3% mortality respectively after 72 hrs of application.
