Evaluation of the potential of some local spices as stored grain protectants against the maize weevil Sitophilus zeamais Mots (Coleoptera: Curculionidae)

Five local spices (Piper guineense, Allium sativum, Afromomum melequata, Xylopia aethiopica and Tetrapleura tetraptera) were evaluated in the laboratory for their ability to protect stored maize against infestation by S. zeamais. Ground products of the spices were applied as direct admixtures at two concentration levels of 1% and 5% to assess for mortality, progeny emergence, damage and repellency. At 1% and 5% concentration, P. guineense caused significant (P 0.05) mortality of weevils. A. melequata and P. guineense were strongly repellent to the weevils while the other three spices showed moderate repellent activity. There was a significant (P 0.05) reduction in damage caused by the weevils with less damage recorded on grains treated with P. guineense, A. sativum and T. tetrptera. Progeny production was also significantly (P 0.05) influenced by P. guineense than the other four spices and the control. The possible protectant potentials of the five spices are discussed.