Efficacy of Eucalyptus Leaf (Eucalyptus camaldulensis), Moringa Seed (Moringa oleifera) and Pirimiphos-methyl Powders against Maize Weevil (Sitophilus zeamais) in Stored Maize

Abstract

Annually, Nigeria loses 20–40% of maize grain due to insect pests attack. However, insect pest control in stored products relied heavily on the use of gaseous fumigants and residual contact insecticides. The control method is limited as it is toxic to beneficials and humans. Efforts have now shifted to the use of edible plant materials as protectants of which the tropics are well endowed with. Therefore, a study was conducted in laboratory in order to evaluate the effectiveness of powders of eucalyptus leaf (Eucalyptus camaldulensis Schlecht,) moringa seed (Moringa oleifera Lam.) and Pirimiphos-methyl against maize weevil (Sitophilus zeamais) on stored maize (Zea mays L.). • camaldulensis leaf powder showed 100% repellence effect at a concentration of 2.0 g / 20 g maize seeds while M. oleifera seed powder had 75% repellence effect against S. zeamais. Contact toxicity of E. camaldulensis leaf powder on S. zeamais was 65% at 1.0 g/20 g maize seeds after 96 hours of exposure. Contact toxicity of M. oleifera seed powder on S. zeamais was 60% at 96 hours of exposure at a concentration of 1.0 g/20 g maize seeds. The powders of E. camaldulensis leaf and M. oleifera seed showed promising effects against S. zeamais in stored maize, hence could be incorporated in an integrated approach as alternative to synthetic pesticides when used in reducing weevil infestation in stored maize seeds.