ANTIFEEDANTS ACTIVITIES OF SELECTED BIOPESTICIDES ON THE COCOA MIRID SAHLBERGELLA SINGULARIS HAGL 1895 (HEMIPTERA: MIRIDAE)
Keywords:
Bio-insecticides, antifeedants, cocoa pods, miridAbstract
Cocoa mirids remain one of the most destructive insect pests affecting cocoa production in West Africa, causing substantial economic losses through feeding damage on developing pods. Conventional management relies heavily on synthetic insecticides, which often lead to environmental contamination, pest resistance, and adverse effects on non-target organisms. This study evaluated the antifeedant activity of three commercially available biopesticides; Bioneem EC (azadirachtin-based botanical insecticide), Biocatch WP (Lecanicillium lecanii), and Biomagic WP (Metarhizium anisopliae), against the cocoa mirid Sahlbergella singularis under laboratory conditions. Fresh unripe cocoa pods were collected from cocoa farms in Orimolade and Igba villages in Ondo State, Nigeria. Pods were treated with different concentrations (0.5%, 1.0%, and 2.0%) of the biopesticides and subjected to paired-choice feeding tests using starved mirids. Ten mirids were introduced into each experimental unit containing both treated and untreated pods, and feeding lesions were counted after 24 hours using a magnifying lens. The experiment followed a completely randomized block design with four replicates. Data were analyzed using analysis of variance (ANOVA), Pearson correlation coefficient, and Duncan’s Multiple Range Test at 5% probability. Results showed significant reductions in feeding damage on treated pods compared with untreated controls. Pods treated with the biopesticides recorded an average of 6–9 feeding lesions, whereas untreated pods recorded approximately 91–97 lesions per ten mirids. Pyrinex 48EC, used as a synthetic reference insecticide, recorded an average of 17 lesions. No significant difference (p>0.05) was observed among the three biopesticides, but all treatments differed significantly from untreated controls (p<0.05). The findings demonstrate strong antifeedant and repellent properties of the tested biopesticides, highlighting their potential as environmentally sustainable alternatives for integrated management of cocoa mirids.
