[01] Atewoja Yejide Yemisi, Department of Crop, Soil and Pest Management, The Federal University of Technology, Akure, Nigeria. [02] Ofuya Thomas Inomisan, Department of Crop, Soil and Pest Management, The Federal University of Technology, Akure, Nigeria. [03] Idoko Joy Ejemen, Department of Crop, Soil and Pest Management, The Federal University of Technology, Akure, Nigeria. [04] Adebayo Raphael Abiodun, Department of Crop, Soil and Pest Management, The Federal University of Technology, Akure, Nigeria.

Rice husk ash (RHA) has previously been proven to be lethal to storage beetles. RHA obtained from six different Nigerian rice varieties were evaluated for their protective capability against grain damage by Callosobruchus maculatus Fabricius and Sitophilus zeamais Motschulsky under ambient laboratory conditions (28 ± 2ºC and relative humidity of 75 ± 5%) in Akure, Nigeria. Each ash was produced adopting standard methods, and evaluated at 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0/ 20 g of grain dosages against 10 adults of each beetle species (5 males and 5 females). Whilst oviposition, adult emergence and seed damage was observed for C. maculatus, only adult emergence and seed damage was observed for S. zeamais, post infestation. All ash types generally significantly protected grain from damage by the two beetles in comparison with the unprotected control. Oviposition by C. maculatus was lowest in grain protected with RHA obtained from Jemila rice variety from Kaduna State, irrespective of rate of application. Irrespective of beetle species, Jemila RHA showed lowest adult emergence, seed damage and seed weight loss. Jemila RHA may be used to mitigate grain damage by seed beetles, and is recommended for consideration for combination with other non-chemical methods in integrated stored grain protection.

Rice Husk Ash, Callosobruchus maculatus, Sitophilus zeamais, Grain, Damage

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