Role of some plants powder in controlling the red flour beetle, Tribolium castaneum in the laboratory

The red flour beetle (Tribolium castaneum) is a major pest causing significant damage to stored grains, leading to substantial economic losses. This study evaluated the repellent and insecticidal effects of red pepper (Capsicum frutescens), moringa (Moringa oleifera), and eucalyptus (Eucalyptus camaldulensis) powders against T. castaneum larvae and adults. Plant materials were dried, ground, and applied to crushed rice grains at concentrations of 1%, 2.5%, and 5%. The repellent effect was assessed by recording the number of insects leaving treated grains over five days, while the insecticidal effect was determined by calculating the corrected mortality percentage after seven days of treatment. Results showed that eucalyptus powder at 5% concentration had the highest repellent effect on larvae, with an overall repellence rate of 46.01%. Red pepper powder at 5% concentration was most effective in repelling adults, with an average repellence rate of 71.46%. Moringa powder at 5% concentration exhibited the highest insecticidal effect, causing 66.67% mortality in both larvae and adults. The efficacy of plant powders increased with higher concentrations. The repellent and insecticidal effects of these plant powders may be attributed to their volatile compounds, secondary metabolites, and physical properties. This study demonstrates the potential of using red pepper, moringa, and eucalyptus powders as eco-friendly alternatives to synthetic insecticides for protecting stored rice grains from T. castaneum infestation. Further research is needed to evaluate the effectiveness of these plant powders in protecting other stored crops from various storage pests.