Insecticidal Activity of <i>Annona squamosa</i> l. Seed Extracts against the Red Flour Beetle, <i>Tribolium castaneum</i> (Herbst)

Abstract

Insecticidal activity of the seed extracts of custard apple, Annona squamosa L. in petroleum spirit, ethyl acetate, acetone and methanol against Raj, CR 1, FSS II and CTC-12 strains of the red flour beetle, Tribolium castaneum (Herbst) was studied. The seeds were dried, powdered and extracted in Soxhlet`s apparatus in the solvents below 60°C. Extractions were applied on larvae and adult beetles in film residue methods and mortality was recorded after 24 h. For larval bioassay the highest toxicity was recorded for petroleum spirit extract (LD₅₀= 0.03?g cm^-2) in Raj strain and the lowest toxicity was for methanol extract (LD₅₀=15.697?g cm^-2) in FSS II strain. In adults petroleum spirit extract offered highest toxicity (LD₅₀= 58.697?g cm^-2) in CTC 12 strain and the lowest toxicity (LD₅₀=22004.710?g cm^-2) was for acetone extract in CR 1 strain. LD₅₀, 95% confidence limits and regression equations are presented. Key words: Tribolium castaneum, Annona squamosa, custard apple, LD₅₀ J. bio-sci. 14: 107-112, 2006