Insecticidal activity of Annona squamosa L. seed extracts against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

Crude Annona squamosa L. seed extracts were fractionated and purified to isolate the insect active fraction. Fractionation of crude extracts and purification of active components were done with solvent partitioning and chromatography. Thin layer chromatography of the extracts, developed in 9:1 chloroform methanol, yielded seven isolates with varying degrees of polarity. Insecticidal activity of the extracts against Ceratitis capitata (Wiedemann) was evaluated in the laboratory. Extract bioassays with respect to medflies clearly demonstrated that A. squamosa contained a factor toxic to insect. Assays successfully guided extract fractionation to yield one or two active insecticidal compounds. Topical application of the extract revealed that the insect active fraction was 2.5 x 10 to the minus third power and 2.07 x 10 to the minus third power as toxic as malathion to male and female flies, respectively. Dipping medfly larvae in chloroform extract did not affect pupation and adult emergence nor caused any morphogenetic effect in the ensuing pupae and emerging adults