Eugenia aromatica O. Berg and Afromomum melegueta K. Schum botanical entomocides as possible synergetic protectant against Callosobruchus maculatus (Fabricus) (Coleoptera: Chrysomelidae) infestation on stored cowpea (Vigna unguiculata (L.) Walp.)

Abstract

Summary Introduction: Post-harvest protection of food grains against stored products insects’ infestation is a complementary means towards ensuring food security. Objective: Powders and extracts from Eugenia aromatica O. Berg and Aframomom melegueta K. Schum are to be evaluated for their synergetic effects on Callosobruchus maculatus Fabricus under laboratory conditions. Methods: The products were applied at rates of 1 g/20 g and 1% conc./20 g cowpea seeds respectively. Results: Findings show that E. aromatica products was more effective by evoking 100% mortality within 24 and 48 h, while synergetic effects of the two products evoked 100% mortality at 72 and 96 h. The survival of the bruchids treated with plant powder from eggs to adults indicated that, control had significant (p<0.05) progeny development (75.50%) in comparison with sole application of E. aromatica and combination with A. melegueta which recorded no progeny development. Conclusion: The study revealed that the plant products exerted toxicity effect against cowpea bruchid. Thus, they can be used to prevent egg hatching and thereby helping in the management of cowpea seeds.