Bioactivity of the Extracts from Stem of Mirabilis jalapa L.

The extracts from stem of Mirabilis jalapa L.are used to determine their bioactivity to Plutella xylostella L.,Pieris rapae L.and Prodenia litura Fabr.The results indicated that the chloroform extract has the strong killing egg effects(82.76% of the corrected mortality after 5d to Pieris rapae L.and drive effects 87.40% of drive rate after 3d to Plutella xylostella L.) The petroleum ether extract has the better contact effect to 4th age larva of Pieris rapae L.and the corrected mortality are up to 85% after 3d and 100% after 5d respectively,the chloroform extract has the strong anti-feeding effect to 4th age larva of Pieris rapae L.and the rates of anti-feeding effect are 96.80% after 3d and 99.67% after 5d respectively,and the chloroform extract has the better toxicity effect to 4th age larva of Pieris rapae L.and the toxicity effect is up to 87.50% after 7d.