Effect of feeding from different sugar beet cultivars on Lixus incanescens adults gut protein content and α-amylase activity, and the enzyme inhibition by triticale and rye protein extracts

 Sugar beet long snout weevil Lixus incanesncens is spread in almost all sugar beet fields in the Iran and causes economic quantitative and qualitative damage to sugar beet. In current study, the effect of four different sugar beet cultivars; Efesos, Anaconda, Aigrette and Premiere, on weight of adults, gut protein content, gut α-amylase activity and its inhibition with rye and triticale seed protein extracts were compared. The highest weight (20.33 mg) was seen in Efesos cultivar fed adults and no significant difference was recorded between the others. The gut protein content and α-amylase activity in the adults fed on different sugar beet cultivars were different significantly and the least and highest values were recorded in Premiere and Efesos, respectively. According to the results, triticale protein extracts inhibited the gut α-amylase activity of all adults fed on four sugar beet cultivars and there was no significant difference between them. The highest inhibitory rate (93%) was recorded in adults fed on Premiere. Also, the rye protein extract inhibited the Premiere fed adults digestive α-amylase activity up to 98% and no significant difference was observed between the others. Consequently, rye and triticale protein inhibitors can be considered as one of the integrated pest management factors for the control of this pest. Also, Efesos and Premiere can be reported as desirable and undesirable cultivars for this insect, respectively.