SOME PROPERTIES OF ? -AMYLASE IN THE SALIVARY GLAND OF EURYGASTER INTEGRICEPS (PUT) (HET.: SCUTELLERIDAE)Abstract : Studying insect digestive enzyme is important for understanding the function of their digestive systems. Today, many attentions are focused on plant enzyme inhibitors and their application in producing transgenic plants. Determining the properties of all digestive enzyme is the first step that should be observed. Enzyme was active at 25 to 50°C and its considerable activities were observed at 35 to 50°C. However, the highest level of activity occurred at 45°C. So, the optimum temperature for the enzyme activity was 45°C. Optimum pH for enzyme activity was 5. The amylase activity in anterior and posterior lobes and accessory gland of the salivary glands complex were 0.578, 1.545 and 0.405 U/mg protein, respectively, and were significantly different at P<0.01. The effects of the mineral compounds on adults? á-amylase activity were significant (P<0.01). Copper chloride, ammonium sulfate, sodium nitrate, magnesium chloride, magnesium nitrate (all at concentrations of 1 and 3 mM) and ammonium phosphate (1 mM) significantly inhibited the á-amylase activity in E. integriceps.