Stomach action of osthole to 3rd instar larvae of Plutella xylostella and its effects on activities of glutathione-S-transferase(GSTs)and acetylesterase(AChE) were studied in the laboratory.The results showed that the osthole had stomach action on the Plutella xylostella larvae.At a concentration of 2 mg/mL,the corrected mortality of the larvae was 37% at 12 h after osthole application,while the corrected mortality of larvae was 93% at 72 h.The LC50 for the 3rd instar larvae was 1 521.25 mg/mL,865.93 mg/mL ...