author(s)
Gbadebo FM, Idoko JE and Adebayo RA

abstract
Laboratory experiments were carried out in order to evaluate the insecticidal effects of Eugenia aromatica flower buds and Piper guineense fruit powders on Callosobruchus maculatus (F) and Sitophilus zeamais (M) under hermetic and non-hermetic storage conditions. The effects of the powders were observed at different dosage rates: 0.0g (control), 0.2g, 0.4g, 0.6g, 0.8g and 1.0g per 20g of cowpea seeds and maize grains. Percentage beetle and weevil mortality were observed at 12, 24, 36, 48 hours and at 24, 48 and 72 hours respectively. The results revealed 100% mortality of adult C. maculatus on cowpea seeds treated with E. aromatica powder and P. guineense at 36 hours and 48 hours respectively. P. guineense powder on S. zeamais evoked the highest adult mortality of 56.7% at 72 hours post treatment under hermetic storage condition. Low bruchid and weevil mortality were observed on cowpea seeds and maize grains treated with the plant powders when stored in non-hermetic storage condition regardless of the period of exposure of the insects to the plant powders. In a further evaluation of the plant powders on the survival and development of C. maculatus and S. zeamais, adult emergence were drastically reduced in all the treated seeds stored under hermetic condition than those stored under non-hermetic condition. The effectiveness of the plant powders in reducing damage due to the control of C. maculatus and S. zeamais infestation during storage was proved in this work and the plant materials exhibited promising potentials as a substitute to the use of synthetic insecticides in hermetic storage of seeds.