BIO-INSECTICIDAL EFFICACY OF BOTANICAL EXTRACTS OF CITRONELLA AND CINNAMON AGAINST TRIBOLIUM CASTANEUM, SITOPHILUS ORYZAE AND DROSOPHILA MELANOGASTER UNDER LABORATORY CONDITIONS

Synthetic insecticides result in environmental pollution, pest resistance and residues problems; hence, focus is now given on plant based products for pest control. This study aims to assess the efficacy of two plant extracts, Citronella and Cinnamon against the two stored grain pests, Tribolium castaneum, Sitophilus oryzae, and the fruit fly Drosophila melanogaster under laboratory conditions. The extracts of two medicinal plants, Citronella and Cinnamon were applied separately at various concentrations (1, 2 and 3 mL/petri dish) on filter papers in petri dish containing the test insects. Mortality was recorded after one, two and three hours exposure. The three hours exposure at 3mL/dish caused 90-99% mortality. Mortality was largely dependent on exposure time and concentrations of both the extracts. A decrease in concentration resulted in low fatality and vice versa. Mortality in control and solvent batches was less than 10% in all the experiments. Our results confirm that the extracts of Citronella and Cinnamon are highly effective against Sitophilus oryzae, Tribolium castaneum and Drosophila melanogaster. These findings further suggest the need for molecular studies of these medicinal plants.