Study on the bioactivity of extracts from Corydalis adunca against Mythimna separate

The insecticidal activities of Corydalis adunca extracts against Mythimna separate were studied through immersion and sandwich methods. The results showed that the contact effect of methanol extract against the larvae was the strongest and the corrected mortality was 15.5%. Contact effect of chloroform fraction from the methanol extract against the larvae was the strongest, its corrected mortality was 87.5%, the median lethal concentration (LD50) was 13.07 g/L. The chloroform fraction had very strong development inhibition and stomach poisoning effects, development inhibition rate and corrected mortality were 88.66% and 91.38% respectively.