Insecticidal and Repellent Properties of Subtropical Plant Extracts Against Pulse Beetle, Callosobruchus chinensis

Abstract

Extracts of eight plants local to Oman, namely Qarat (Acacia nilotica), Mustafal (Annona squamosa), Shereesh (Azadirachta indica), Luban (Boswellia sacra), Kheshkhash (Crotolaria juncea), Zebrot (Jatropha dhofarica) Yas, (Myrtus communis) and Suwwad (Suaeda aegyptiaca) were prepared by steeping shaded dried leaf/ seed powder of each plant in water and solvent (methanol or ethanol). The extracts were tested for their insecticidal and repellent properties against the pulse beetles, Callosobruchus chinensis. The extracts from the seeds of A. squamosa recorded l00% mortality of beetles within twenty and four hours of their exposure to methanol and ethanol extracts, respectively. The other extracts that caused high mortality were from A. nilotica, C. juncea, M. communis and S. aegzptiaca in methanol and B. sacra, J. dhofarica, S. aegptiaca and commercial neem in ethanol. Extracts of M. communis in methanol were highly repellent to the beetles compared to other extracts. Legume seeds treated with extracts of A. squamosa were not repellent, rather the beetles were attracted to them.

Keywords

• insecticides, repellents, subtropical plant extracts, pulse beetle.