Chemical composition and toxicity of some Agro waste-derived insecticides against Angoumois grain moth, Sitotroga ceralella (Olivier) [Lepidoptera: Gelechiidae] infesting stored paddy grains

Abstract

Background Agriculture being one of the major practices in the world has contributed to environmental pollution, especially in developing countries where there were no equipment to recycle the agricultural wastes. Considering the high level of infestation of paddy by Sitotroga cerealella and the high level of pollution caused by agricultural wastes, this research investigated the chemical composition and toxicity of agro wastes (rice husk, maize cob, groundnut and cowpea pods) as eco-friendly protectants of paddy against Sitotroga cerealella. Parameters assessed include adult mortality, oviposition, adult emergence and egg hatchability. Gas chromatography and mass spectrophotometry were used to isolate and characterize the active compounds present in the most effective crude extract. Results The results of the study revealed that all agricultural wastes showed high mortality effect on S. cerealella. Cowpea pod powder was the most toxic to adult paddy moth that caused 33.33%, 36.67%, 46.67%, 50% and 60% mortality of S. cerealella at concentrations 0.1 g, 0.2 g, 0.3 g, 0.4 g and 0.5 g/20 g of paddy grains after 24 h of exposure, respectively. The Cowpea pod, groundnut pod and maize cob extracts caused 100% mortality of S. cerealella at concentration 0.5 ml/20 g of paddy grains after 96 h of exposure, respectively. The lethal concentrations LC50 and LC90 of cowpea pod after 24 h were 0.16 and 0.64 ml which were the lowest of all agro waste extract tested. GC–MS analysis revealed that 19 chemical compounds were present in cowpea pod extract, 9, 12-Octadecadienoic acid (a methyl ester) has the highest percentage total of 39.57% and 4-Pentenal, 2-methylene (0.12%) has the least percentage total. Conclusion All the observations revealed that cowpea pod was the most effective. The findings also suggested that the selected agricultural wastes have a promising insecticidal potential and can be used as alternatives to synthetic chemical insecticides for the control of stored product insects.

Phytochemical compositions and insecticidal efficacy of four agro-waste used as biological control of cowpea beetle, Callosobruchus maculatus (Fab.) [Coleoptera: Bruchidae]

“…This shows that mating took place but their mean adult emergence was low when compared with the controls. The act of weakening of adults by botanical powders and extracts may make them lay fewer eggs than expected, leading to limited hatchability to larvae and final metamorphosis to adults (Adedire and Lajide 2003; Obembe et al 2020;Ashamo et al 2021a). The inability of insect eggs to develop into adults may be due to the effect of the powders and oils on the developmental stages of the insect which was unable to feed on treated seeds that prevent them to fully cast off their old exoskeleton which typically rained linked to the posterior of the abdomen (Trindade et al 2008;Oigiangbe et al 2010).…”

“…The major constrictions in food production in developing nations are the damage caused by insect pests and pathogens (Ashamo et al 2021a). Damage of about 40% loss is recorded in countries where modern storage facilities are not available (Ofuya 2001).…”

“…Control of stored product insects using materials of natural origin is receiving much attention nowadays as a result of their little environmental health hazards (Mohan and Fields 2002;Nadra 2006;Emeasor et al 2005;Ileke et al 2020bIleke et al , c, 2022a. Attention is shifting towards the use of agro wastes in insect pest management (Obi et al 2016, Ashamo et al 2021aIleke et al 2022b). There is a need for more work is on the insecticidal efficacies that may be present in some of these agro wastes.…”

Application of Two Ocimum Species Powders in the Control of Red Flour Beetles, Tribolium castaneum Herbst (Coleoptera: Tenebronidae), during Wheat Grain Storage

“…This insect pest favors goods that are pulverized or powdered and contain flour [5,8]. Numerous cereals, seeds, and other raw materials such as dried fruits, beans, cocoa beans, almonds, spices, oil seeds, cotton seeds, and processed foods were been reported to be infested by the [10][11]. This beetle is significantly reducing the number and quality of products that are stored all over the world [12].…”

Insecticidal Potentials of Capsicum chinense (Jacq) and Garcinia kola (Heckel) Extracts on Callosobruchus maculatus (Cowpea Weevil) Infestation

“…According to Ashamo et al (2021a), the damage caused by pests and diseases is one of the major restraints on food production in impoverished countries. In countries where there are no contemporary storage sites, a loss of roughly 40 % is reported (Ofuya, 2001).…”