Effects of different prey regimes on activities of digestive enzymes in Andrallus spinidens (Hem.: Pentatomidae)

The responses of digestive enzymes of the midgut of Andrallus spinidens Fabricius nymphs، toward feeding on Chilo suppressalis Walker، Galleria melonella (L.)، Plodia interpunctella (Hübner) and Ephestia kuehniella Zeller were analyzed to find the most satisfactory species for a mass rearing program. The nymphs were fed from 2nd instar until 24 hours after the emergence of the 5th instar. The highest weight gain was recorded in the nymphs that fed on C. suppressalis and G. melonella، and the highest amount of total protein found in the nymphs feeding on G. mellonella. Carbohydrase activities including α-amylase، α- and β-glucosidase were the highest in the nymphs that were fed on C. suppressalis and E. kuhniella. The highest TAG-lipase activity occurred in the nymphs feeding on G. mellonella and the related gel electrophoresis showed distinctive zones in comparison with the rest. General proteolytic was performed at two pH values and the highest activity recorded in G. melonella (pH 8) and E. kuehniella (pH 6). The highest activities of serine proteinases، cysteine proteinases and two exopeptidases were found in the nymphs fed on G. mellonella and E. kuehniella. Correlation between digestive enzyme activities in A. spinidens and nutritional composition of their feeds may reflect the adaptive nature of the enzymatic profile. These findings can efficiently help to find the most suitable species for an efficient control program and successful mass rearing of the biocontrol agent.