Abstract: To study the effects of feeding by Pachypeltis sp. on the defense enzymes in Mikania micrantha， activities of three enzymes， peroxidase (POD)， polyphenol oxidase (PPO) and phenylalanine aminolyase (PAL)， were evaluated in M. micrantha leaves at time points of 12h， 24h， 48h and 96h postfeeding under laboratory conditions. The results showed that activities of POD and PAL decreased while PPO increased. At 48 h after feeding， POD and PAL activities of the treatment group decreased by 5191% and 7500% respectively， while that of the control group decreased by 3234% and 4986%. PPO activity of the treatment group increased by 37173%， while that of the control group increased by 12113%．

Key words: Mikania micrantha, Pachypeltis sp., feeding, defense enzymes