Abstract:
The insecticidal properties of the ether extract of Anona squamosa seeds have been examined and compared with those of DDT and pyrethrins. As a contact poison, the extract is toxic to Musca nebulo and Tribolium castaneurn adults; DDT is 7 and 10 times more toxic than the extract against M. nebulo and T. castaneum respectively. The extract acts as a stomach poison against the larvae of Bombyx mori, but its activity is 10 times less than that of DDT. As an ovicide, the extract is toxic to the eggs of B. mori; 1 per cent solution of the extract effects 84-86 per cent kill as compared to 96-100 per cent kill effected by 0·04 per cent pyrethrin solution. The extract in addition acts as a repellent. It has poor residual toxicity against M. nebula, the toxicity being negligible 8 days after application.By treating the ether extract with petroleum ether, an insoluble resin is obtained which is 6 times as toxic as the ether extract, particularly as a contact poison against M. nebulo.
