‎Residual Toxicity of Piper Nigrum L. Powder Against the Susceptibility of Stored Maize Cultivars to Infestation by Sitophilus Zeamais Motschulsky (Coleoptera: Curculionidae)

Maize (Zea mays L.) cultivars grown in Egypt are not only numerous, but also show a wide diversity of exposure to stored grain pests causing damages that may threaten food security. Thus, the aim of this study was to assess the level of susceptibility of maize cultivars to infection by Sitophilus zeamais (Motschulsky), a voracious insect pest of stored maize. Likewise, to evaluate the efficacy of black pepper, Piper nigrum L. powder as an insecticide against this pest to protect stored maize. The susceptibility index values showed that cultivars THW-310 and THY-352 were more susceptible to infection by S. zeamais, and the levels of some amino acids were higher than cultivars SHY-162 and SHW-10, which showed relatively low infection. In all maize cultivars, application of P. nigrum powder reduced the severity of S. zeamais infestation, significantly improved seedling growth, and % germination after six months of maize storage, compared to the untreated samples. The promising P. nigrum powder could be recommended for use as a part of an integrated pest management program in stored maize, particularly for a long storage periods.