Pesticidal Activity of Wild Mushroom Cantharellus cibarius (FR) Extracts against Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) in Stored Maize Grains

Abstract

Grain damage due to pest infestation is among the top challenges facing cereals production. Maize grains being among the staple food in different parts of the world is prone to destruction by pests such as vertebrates, fungi and insects who are known to affect maize before harvest and during post harvest storage. Sitophilus zeamais is among the potential maize grains infestants. The efforts to control the pest highly depends on the application of synthetic pesticides which are faced by challenges of limited access, fear for toxicity, development of resistance among the pests and environmental pollution. This study aimed at assessing the toxicity, anti-feedant and repellence activities of crude methanol extracts of wild mushroom Cantharellus cibarius on Sitophilus zeamais in stored maize grains towards searching for alternative means of pest control. Assessments were conducted using six levels of concentrations ranging between 0.05 to 0.5 % w/w. Nontreated grains and treated grains with 2% Actellic gold TM 2% dust (0.05% w/w) were used as negative and positive controls respectively. Three replicates were made for each treatment and experiments were conducted in a completely randomized design. The methanol extract at 0.5% w/w concentration demonstrated high toxicity 21 days after treatment killing 66.7% of the pest. Similarly, a 92.5% reduction in grain damage was observed at 0.5% w/w 21 days after treatment compared to nontreated controls. Furthermore, the extracts indicated pest repellence of 98.3% after 24 hours of exposure. The findings render C. cibarius a potential biopesticide for use by subsistence farmers against maize storage pests to support the ongoing Integrated Pests Management strategies. Further studies are recommended on the appropriate frequency and rate of application as well as the maximum duration of protection that can be offered by the extracts.