Nutritional Physiology of the Khapra Beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) Fed on Various Barley Cultivars

The Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), is known as one of the most serious pests of grains in many parts of the world. In this study, the effect of nine barley cultivars (‘Bahman’, ‘CB-84-10’, ‘Fajr 30’, ‘Makuyi’, ‘Nosrat’, ‘Yousof’, ‘13A1’, ‘18A1’, and ‘19 A1’) and a wheat cultivar (‘MV17’, as a control) was determined on the nutritional indices and digestive enzymatic activity of T. granarium at 33 ± 1°C, relative humidity of 65 ± 5%, and a photoperiod of 14:10 (L:D) h. The highest and lowest values of larval weight gain of sixth instar were detected on wheat (0.757 ± 0.068 mg) and cultivar Bahman (0.342 ± 0.071 mg). Also, T. granarium larvae fed on cultivar Bahman had the lowest value of efficiency of conversion of ingested food (10.90 ± 2.09%) as compared with wheat and other barley cultivars. Also, the highest midgut amylolytic and proteolytic activities of sixth instar were on cultivar Bahman (0.364 ± 0.024 mU/mg and 80.54 ± 1.73 U/mg, respectively) and the lowest activities were on cultivar Nosrat (0.043 ± 0.004 mU/mg and 7.15 ± 0.01 U/mg, respectively). It is concluded that barley cultivar Bahman was the most unsuitable host for feeding of T. granarium.