Digestion and protein metabolism of Trogoderma granarium (Coleoptera: Dermestidae) fed on different barley varieties

The Khapra beetle, Trogoderma granarium Everts, is one of the most important pests of grains which rapidly infests durable stored products in hot and dry conditions. In the current study, effects of omit ten varieties of barley (Abidar, Bahman, Line20, Line22, Line30, Lisivi, Lokht11, Makuyi, Sahand and Sahraa) were determined on digestive enzymes and protein metabolsim of T. granarium larvae under laboratory conditions as 33 ± 1 °C, 65 ± 5% RH and photoperiod of 14:10 (L: D) h. The highest and the lowest activities of α-amylase were observed in T. granarium larvae fed on Line30 and Lisivi varieties, respectively but the glucosidases showed the highest activities followed by feeding on Lokht 11. Also, the latter variety caused the highest lipase activity in the larvae while Abidar, Line20, Lisuei and Sahand imposed the lowest lipase activity. The highest activities of serine proteases including trypsin, chymotrypsin and elastase were detected in the larvae fed on Line 30 but the two exopeptidases, amino- and carboxypeptidases, showed the highest activities when the larvae fed on Lisuei. All the three aminotransferses had the highest activities in the larvae fed on Lokht 11 as the related individuals contained the maximum amount of protein compared to other ones. Results of the current study highlighted Line30 as the most suitable variety to be digested by serine proteases and α-amylase but Lokht11 is appropriately digested by glucosidases and lipase which emboss their susceptibilities to T. granarium. Our findings on digestion and protein metabolism imply on susceptibility of varieties Line30 and Lokht11 to T. granarium larvae.