Comparative Efficacy of Piper guineense Pinmuphos-Methy (Schum and Thonn.) Powder and Dust Against Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae) in Stored Maize.
ASAWALAM, E.F. AND EMOSAIRUE, S.O.
Nig. J. Entornol. 23: 30 – 33 (2006)
ABSTRACT: Powdered seeds of black pepper, Piper guineense (Schum and Thonn) applied at 0.1 g, 0.2g,
0.3g, and 0.4g/50g of maize grains evaluated for maize weevil, Sitophilus zeamais Motsch, control, An insecticide treatment (lg pirirniphos-methyl /50g) and an untreated control were included. The effect of particle size of the seed powder on maize weevil control was also evaluated. The experiments were laid in completely randomized design with four replications. Percentage weevil mortality was recorded at 3,5,7, 14 and 21 days after infestation. At 5 days post-treatment, all rates of the seed powder caused significantly higher mortality than the level in control; the synthetic insecticide caused 100% mortality. The finer particle sizes (1 mm, 600um) of the pepper seed powder
compared favourably with pirimiphos-methyl in controlling S. zeamais. In addition, grains treated with the seed powder showed significant reduction in the number of progeny derived from surviving S. zeamais. The powder reduced weight loss and induced high germination percentage. There was no observable feeding damage on grains treated with the higher rates and finer particle sizes. The results provide scientific rationale for the use of P. guineense in post-harvest protection.