Insecticidal Activity and Action Ways of Extract from Fruits of Gleditsia sinensis Lam. against Mythimna separate

Insecticidal activity of extract from fruits of Gleditsia sinensis and its action ways against Mythimna separate by immersion and sandwich methods were studied.The results showed that 85 % ethanol extract from the fruits had very strong contact toxicity against the 5th instar larvae of M.separate with the corrected mortality of 70 % when the treatment concentration of the extract was 76 g/L.The extract had very strong antifeedant activity against the 3rd instar larvae of Pieris rapae with antifeedant rate of 100 % when the treatment concentration of the extract was 380 g/L,and also had some extent contact toxicity against Tetranychus cinnabarinus with the corrected mortality of 33.4 % when the treatment concentration of the extract was 3.8 g/L.Action ways of the extract against the larvae were very strong contact toxicity,stronger antifeedant(antifeedant rate was 67.38 %)and stomach poisoning(corrected mortality was 42.87 %)actions as well as very strong development inhibition action(development inhibition rate was 100 % 3 days after treatment).The extract had no fumigation,anaesthesia and systemic actions against the larvae,and had no contact toxicity to the pupae and ovum.