Entomotoxicant potential of Christmas bush, Alchornea cordifolia (Schum. & Thonn.) leaves powder in the control of maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) infesting stored maize
Koomson CK and Oppong EK
The efficacy of leaf powder of Alchornea cordifolia against the maize storage pest, Sitophilus zeamais on stored maize was investigated in the Integrated Science Education Department laboratory of the University of Education, Winneba, Central Region, Ghana, at a temperature of 30±2̊C and 75±5% relative humidity. A. cordifolia leaf powders were added to 20.0 g of grains at the following rates of 3.0g, 4.0g, and 5.0g to assess contact toxicity, damage assessment, progeny production, repellency and seed germination ability. Results showed that the plant material was toxic to the insect (P<0.05). The leaf powder of A. cordifolia applied at 5.0g concentration greatly caused the highest mortality of 93% after 21 days. It also repelled almost 90% of the maize weevils and significantly inhibited adult emergence up to about 97%. The 5.0g concentration of the leaf powder further offered a protection of nearly 98% to the maize seeds against damage by the weevils compared to other concentrations (P<0.05). The leaf powders at all the concentrations also had no effect on germination. The result revealed that A. cordifolia powder can be used as an entomotoxicant against S. zeamais and its incorporation into traditional storage pest management and integrated pest management is strongly recommended in developing countries.