Phytochemical screening and the toxic effect of Azadirachta indica, zingerber officianalis and Annona squamosa against white fly, Bemesia tabaci.

Abstract

The present study was designed to evaluate the toxicity of different botanicals against the whitefly Bemesia tabaci. Methanolic and aqueous extracts of different plants (Azadirachta indica, zingerber officianalis and Annona squamosa) known for their medicinal value were prepared by soxhlet extraction which werethen evaluated for insecticidial activity against eggs and nymphs of Bemesia Tabaciat different concentrations. The results showed that the methanolic and aqueous extracts of Azadirachta indica showed high to moderate insecticidial activity against eggs and nymphs (79.00% and 100.00±0.1) followed by Zingerber officianalis (76.09% and99.12± 0.1) at 25 % concentrations after 72 hours of treatment respectively. The aqueous extract of Annona squamosa showed least toxic effect (56.29 % and 50.00)at 5% concentration after 48 hours of treatment. A gradual increase in the mortality was found with the increase of concentration and duration of the treatment. The overall efficacy of the three pesticides against the survivorship was in the order of Azadirachta indica>zingerber officianalis>Annona squamosa. Hence, the extracts from these plants could be used as an effective and environmentally sustainable bio-insecticide for the control of whiteflies, Bemisia tabaci.