Insecticidal, antifeedant and growth-inhibition activities of different extracts from Pedicularis spicata against Plutella xylostella

Abstract

Insecticidal, antifeedant and growth-inhibition activities of five different extracts (petroleum ether, chloroform, ethyl acetate, n-butanol and water) from Pedicularis spicata against 3 th c instar larvae of Plutella xylostella were measured by the methods of dipping, leaf dish and feeding. The results showed the extracts of petroleum ether and chloroform have strong activity on 3 th instar larvae of Plutella xylostella. Under the concentration of 4.00 mg/mL, the corrected mortalities of insecticidal activity after 72 h treatment were 100% and 93.1%, respectively, the antifeedant rates were 69.9% and 72.7% after 48 h, growth inhibition rate were 74.2% and 72.6% after 48 h, pupation rates were 53.3% and 57.8%, adult emerging rates were 40.0% and 33.3 %. Compared to the two extracts, the extracts of ethyl acetate, n-butanol and water displayed less potent or no activity on the 3 th instar larvae of Plutella xylostella. © 2012 Springer-Verlag GmbH.