www.ccsenet.org/ijb International Journal of Biology Vol. 3, No. 2; April 2011 Published by Canadian Center of Science and Education 185 Evaluation of Seed and Fruit Powders of Capsicum annum and Capsicum frutescens for Control of Callosobruchus maculatus (F.) in Stored Cowpea and Sitophilus zeamais (Motsch) in Stored Maize M. O. Oni (Corresponding Author) Department of Biology Adeyemi College of Education Ondo, Nigeria P. M. B. 520, Ondo, Ondo State, Nigeria. Tel: 8-03-430-0943 E-mail: mercyyinka2007@yahoo.co.uk Received: September 03, 2010 Accepted: September 14, 2010 doi:10.5539/ijb.v3n2p185 Abstract Capsicum annum and Capsicum frutescens fruit and seed powders were evaluated in the laboratory for the control of Callosobruchus maculatus (F.) in stored cowpea and Sitophilus zeamais Motschulsky in stored maize. Capsicum frutescens seed powder and Capsicum annum seed powder dust were toxic to C. maculatus and S .zeamais at the rate of 5.0g, 7.5g and 5.0g, per 50g cowpea and 50g maize within 48hrs and 96hrs respectively. This paper highlights the potential of C. frutescens and C. annum seed powders as seed protectants against the test bruhids at higher rates, than their ineffective fruit powders in all parameters assessed. Keywords: Capsicum annum, Capsicum frutescens, Seed powder, Fruit powder, Mortality, Callosobruchus maculatus, Sitophilus zeamais 1. Introduction Cowpea, Vigna unguiculata (L) Walp and maize, ( Zea mays L.) are major dietary staple foods (Ofuya, 2001:Ofuya and Adedire, 2004). Cowpea amounts to 60% daily dietary protein intake of most Nigerians (Oparaeke and Dike, 1998), while maize provide families with much needed nutrients, such as carbohydrates, proteins, fats, vitamin B and minerals (Ashamo, 2007 : Kling and Edmeades, 1997). 100% damage has been reported on unprotected cowpea after 3-5 months storage (Singh, 1997), by Callosobruchus maculatus (F.). Maize has also been reported in the tropics to be heavily infested by various pests, majorly Sitophilus zeamais Motschulsky, with about 30-50% damage after 6 months in storage (Taylor, 1971). Synthetic insecticides employed in the control of insects pests proved effective, very expensive, unavailable at critical periods and they sometimes constitute health hazards to consumers (Adedire 2001: Ofuya, 2001: Oparaeke et al., 1998: Lale, 2002 ).This necessitates continous research towards substitution of harzadous synthetic insecticides for use of cheaper and eco-friendly natural plant products with active safe components, among which are use of powdered plant parts, oils and extracts. However, the use of these synthetic chemicals is also hampered by many attendant problems such as development of insect resistant strains, their toxic residues getting into food of animals and man, workers safety and high cost of procurement ( Sighamony et al.,1990 ).Literature from Nigeria and other West African countries revealed Eugenia aromatica, African brown pepper, Piper guineense, Allium sativum, Pepper derivatives (Su, 1994; Lale, 1992; Onu and Aliyu, 1995; Ashamo, 2007; Oni 2009; Adedire and Lajide, 2001: Ofuya et al,. 2000: Ogunwolu, and Odunlami 1996;Ivbijaro and Agbaje,1986) as safe, affordable and effective natural plant products with some degree of medicinal and insecticidal properties. This paper highlights the results of investigation on three application rates of Capsicum annum Miller and Capsicum frutscens L. fruit and seed powders in the control of C. maculatus in stored cowpea and S. zeamais in stored maize. 2. Materials and Methods 2.1 Rearing of insect pests Adult cowpea storage beetles, Callosobruchus maculatus and maize weevils, Sitophilus zeamais were cultured in No.l kilner jars with meshed lids in Crop, Soil and Pest Management Department of Federal University of Technology Akure, Ondo state, Nigeria in open laboratory through-out the period of research. Standard procedure for culturing seed beetles, Ofuya and Creland, 1995: Olotuah et al., 2007 was followed. Ife- brown, a