Life Cycle and Digestive Physiology of Trogoderma granarium (Coleoptera: Dermestidae) on Various Wheat Cultivars

The Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), is known as one of the world's most damaging pests of wheat and other stored products. The life cycle, nutritional indices, and digestive enzymatic activity of T. granarium in response to feeding on six wheat cultivars (Arg, Morvarid, Nai 60, Parsi, Pishtaz, and Shanghai) were evaluated under laboratory conditions (3361 +/- 1 degrees C, 65 +/- 5% relative humidity, and a photoperiod of 14: 10 [L:D] h). In this research, delayed developmental time of T. granarium immature stages was detected on cultivars Parsi and Morvarid. The highest survival rate of immature stages was on cultivar Arg, and the lowest was on cultivars Morvarid and Parsi. Moreover, the highest mean larval weight and weight gain of larvae were on cultivar Arg, while the lowest ones were on cultivars Parsi and Morvarid. In addition, the lowest values of relative growth rate and proteolytic activity were detected when larvae were fed with cultivars Morvarid and Parsi. Based on the obtained results, it can be concluded that cultivars Parsi and Morvarid were the most unsuitable cultivars for the development and feeding of T. granarium. The resistant cultivars can be recommended to be grown in areas where the damage of T. granarium is high for protecting or at least delaying wheat infestation by this pest.