Insecticidal, Antifeedant and Growth-Inhibition Activities of Different Extracts from Pedicularis Spicata against Plutella Xylostella

摘要

Insecticidal, antifeedant and growth-inhibition activities of five different extracts (petroleum ether, chloroform, ethyl acetate, n-butanol and water) from Pedicularis spicata against 3th 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 3th 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 3th instar larvae of Plutella xylostella.