It was investigated the effect of the population density of the greenbug Schizaphis graminum (RONDANI, 1852) on wheat plants (Triticum aestivum L.) on the activity of the enzymes peroxidase and polyphenoloxidase. The following treatments were used: 10, 30, 50 aphids/plant and the control (without aphids). The peroxidase showed higher activity than the polyphenoloxidase. The highest peroxidase's activity occurred when 30 and 50 aphids per plant were used. On the other hand, for polyphenoloxidase, there wasn't difference in the activity among the three densities used.
Greenbug; peroxidase; polyphenoloxidase
