Pesticidal Activity of Wild Mushroom Boletus satanas Lenz Extracts against Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) in Stored Maize Grains

Abstract

Boletus satanas Lenz (Boletaceae) is a basidiomycete fungus reported to contain monomeric glycoproteins (lectins) which are known to possess insecticidal, larvicidal, ovicidal and anti-nutritional activities. This study was carried out to assess the toxicity, anti-feedant and repellence potential of the crude methanol extract of the mushroom in stored maize grains. Six levels of concentration ranging from 0.05 to 0.5% w/w were used during the assessments. Untreated grains and grains treated with 2% Actellic gold ^TM dust (0.05% w/w) were used as negative and positive controls, respectively. The experiments were carried out in a completely randomized design with three replicates made for each treatment level and controls. The 0.5% w/w methanol extract exhibited the highest mean mortality of 68.3% and 94.2% inhibition in F1 progeny. Moreover, 89.7% reduction in grain damage and 98.3% pest repellence were observed. These findings render credence to the use of B. satanas as a potential biopesticide by subsistence farmers to preserve grains and corroborate the ongoing IPM strategies.

Keywords: Pesticidal activity, Boletus satanas, maize grains, Sitophilus zeamais, grain damage, Tanzania