Influence of wheat cultivars on digestive enzyme activity and protein content of the Sunn pest, Eurygaster integriceps (Hem.: Scutelleridae)

The Sunn pest, Eurygaster integriceps (Puton) (Hem.: Scutelleridae), is an economic pest of wheat that reduces the quantitative and qualitative properties of wheat products. We investigated the effect of E. integriceps feeding on six different wheat cultivars (Ghermez (Red), Noodle, Antanius, Sabalan, Azar 2 (with two types of cultivation), and Sardari) on the protein content in the adult’s gut and fat body and their digestive enzymatic activity. All qualified values of the insect feeding on wheat cultivars differed significantly. The least amount of adult weight and protein content of gut and fat body were observed in the insects fed on Ghermez (Red) cultivar, and the highest amount belonged to the Sardari cultivar. The same results for protein content were obtained from SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Also, the lowest and highest gut α-amylase, pectinase, and protease activities were in Ghermez and Sardari cultivars, respectively. Therefore, it was concluded that the type of wheat cultivar affects the food preference of this insect and, thereby, physiological parameters of the insect gastrointestinal tract. Planting a wheat cultivar like “Ghermez,” which may be resistant, can be a suitable and cost-effective method to decrease the chemicals applied against this pest.