Study on Biochemical properties of some digestive proteases of cherry ermine moth, Yponomeuta padella (L.) (Lepidoptera: Yponomeutidae)

Cherry ermine moth, Yponomeuta padella (L.) (Lep.: Yponomeutidae) is a major pest of Cratagus monogyna in central Zagros region that induces serious damage into this forest,s species in recent years. Larvae feed on leaves and makes web by leaves and lead to reduce of phthosynthesis level by attracting of pollutant and fungies. In this study, biochemical properties of some digestive proteases of the 5th instar larvae of cherry ermine moth were studied in its alimentary canal. Whole of gut was used in experiments. After dissecting, guts were homogenized and centrifuged with distilled water. Supernatant was used in enzyme activity studies. The optimal pH for protease activity in alimentary canal were found 11 in presence of Azocasein and hemoglobin as general substrates. The optimal pH for trypsin and chymotrypsin activity were obtained 10-11 and 11, respectively in presence of BApNA and SAAPPpNA as their private substrates. Optimal temperature for protease activity was 25-30ºC. The inhibitory effect of inhibitors on enzyme activity was sharply. Results showed that the highest inhibition rate in proteolytic activity caused by TLCK. Inhibition percentage TPCK and PMSF was 34.15 and 21.34% respectively. Study on physiological characteristics of digestive enzyme and their inhibitors was done for first time. Y. padella is a serious pest on Cratagus monogyna and Cerasus sp. It seems this research could be benefit in management respect of it.