Management of the Maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curcuiionidae) using Botanical Insecticides on three Maize Genotypes

Abstract

The maize weevil, Sitophilus zeamais, is a major insect pest o f stored maize in Ethiopia. The effectiveness o f three botanicals viz., Neem (Azadirachta indica A. Juss) seed powder (NSP), Mexican tea (Chenopodium ambrosioides L.) powder (MTP) and triplex at three different rates were studied for the management of the maize weevil on three maize genotype (SZSYNA99- F2 -33-4-2 X SC22,
SZSYNA99-F2 -79-4-3 x CML-197 and a commercial variety BH-140. The botanical treatments except NSP caused high mortality (95 - 100%) 7-days after exposure, and reduced progeny emergence and grain damage. However, NSP inflicted significant higher mortality than the untreated check 21 days after infestation. At the highest dosage NSP caused similar mortality with the standard
insecticide, Pirimiphos-methyl 2 % dust, 28 days after infestation. Maize genotypes did not show significant response to the pest. Seed germination was not affected by any o f the treatments. It is, therefore, recommended that MTP, NSP and triplex can be considered as a potential component in an effort to establish integrated management strategy against the maize weevil on maize.