Bioefficacy of Aguaria salicifolia and Plectranthus kirbii leaf powders to protect bean grains against infestation by Acanthoscelides obtectus (Coleoptera: Chrysomelidae)

Abstract

The bioefficacy of Plectranthus kirbii and Aguaria salicifolia leaf powders to protect stored bean against infestation of Acanthoscelides obtectus was assessed. The ability of these plants to induce adult mortality, inhibit progeny production, reduce grain damage and insect population growth, as well as to preserve seed viability was tested at different contents. Plectranthus kirbii and A. salicifolia caused significant mortality to adult A. obtectus. The LC50 of P. kirbii and A. salicifolia were 11.67 and 12.67 g/kg respectively after 10 days of contact. The F1 progeny production was significantly inhibited by both powders. The two powders considerably suppressed population of A. obtectus and reduced weight loss of bean after six months of storage. The seeds treated with P. kirbii and A. salicifolia significantly germinated compared to the untreated ones. Considering these results, A. salicifolia and P. kirbii could be used for the protection of stored beans.