Ginsenosides from the stems and leaves of Panax ginseng show antifeedant activity against Plutella xylostella (Linnaeus)

•The total content of 9 ginsenosides from ginseng leaves and stems was 72.91 mg/mL measured by high-performance liquid chromatography method.•Total ginsenosides extracted from ginseng leaves and stems showed significant antifeedant activity on Plutella xylostella larvae.•The residue rate of 9 ginsenosides in the pest became gradually higher as applied concentration increased.•Feeding with ginsenosides generally resulted in change of the detoxication enzymes activity in Plutella xylostella.