Antifeedant activity of the extracts from bamboo against Helicoverpa armigera and Pieris rapae

The antifeedant activity of the extracts from 10 bamboo species against Helicoverpa armigera and Pieris rapae is reported. The results showed that the extracts of the bamboo at their dose of 10 g/L showed fairly good antifeedant activity to H. armigera. After 12 h, the antifeedant rate was from 95.03% to 74.07%. The antifeedant median concentration (AFC_(50)) of the extracts of Phyllostachys nigra var. henonis and Brachystachyum albostriatum against 3rd-instar larvae of H. armigera was 2.00 g/L and 2.07 g/L respectively. However, the rates descended significantly after 24 h and 48 h. The antifeedant activity of the extract from Bambusa multip lex against 3rd-instar larvae of P. rapae was the best, the antifeedant rate of which was the highest(71.60%) after 24 h. The extracts of P. nigra var. henonis and B. albostriatum showed fairly good antifeedant activity against the 3rd and 4th instar larvae of P. rapae, their AFC_(50) were 2.68 g/L and 3.37 g/L, 2.04 g/L and 2.67 g/L respectively.