Survey of insects and Mites Associated with Stored Rice in Nigeria

Abstract

Insect pest infestation causes quantitative or qualitative losses in stored Rice. Proper identification of the insect species infesting stored Rice is critical for making pest management decisions. This study assesses the species composition and abundance of insect pests of stored Rice in Nigeria. Imported and Local Rice samples each weighing one kilogram were obtained every 6 months from three randomly selected vendors in randomly selected markets in 14 towns in 14 states in Nigeria. 50g were weighed from each sample and kept in vials, covered, strapped with rubber band and kept in the laboratory. The Rice samples were sieved to collect all adult insects present after Six months in storage. Sampling lasted for two years (2016-2017). There were 11 species of insect pests and one Mite species in the stored Imported and Local Rice samples. Most of the species were from the order Coleoptera with the percentage occurrence of 80.9% in Imported Rice and 82% in Local Rice. The insect species composition includes Sitophilus oryzae, Cryptolestes ferrugineus, Sitophilus zeamais, Psocids, Sitotroga cerealella, Ahasverus advena, Tribolium castaneum Oryzeaphilus surinamensis, Oryzaephilus mercator and Rhyzopertha dominica. The Psocid and mite species could not be identified. Sitophilus oryzae was the main insect pest of Rice with the percentage occurrence of 39.23% in Imported Rice and 26.87% in Local Rice. The outcome of this study is very important in planning control measures as the knowledge of the species composition and abundance of insect pests is an important component of pest management in stored Rice in Nigeria.