The potency of the medicinal plant, Eugenia aromatica as a biocide against storage insect pests of cowpea and maize was assessed in the laboratory. Different treatment doses 0.0g (Control), 0.5g, 1.0g, 1.5g and 2.0g of E. aromatica were applied on maize seeds infested with Sitophilus zeamais and cowpea seeds infested with Callosobruchus maculatus. The treated samples were monitored at different hours of exposure, 24hrs, 48hrs, 72hrs, 96hrs and 120hrs.The lethal time LT50 for each dosage level for both S. zeamais and C. maculatus were determined. The earliest LT50 for S. zeamais was observed in 48hrs at 1.5g (51.07± 12.38) while the LT50 for C. maculatus was observed in 48hrs at 1.5g (51.07± 2.23). The percentage (%) mortality for S. zeamais and C. maculatus were also determined. It was observed that for S. zeamais, 2.0g at day 5 gave the highest % mortality (88.87%) while for C. maculatus, 2.0g at day 5’ gave the highest % mortality (100%). The result shows that E. aromatic is more effective on C. maculatus than S. zeamais. It is concluded that E. aromatica is an effective plant material that can be used to control insect pests.
Key Words: Eugenia aromatic, Lethal time, Sitophilus zeamais, Callosobruchus maculatus, Cowpeas, Maize