Papilio machaon(Linnaeus) midgut α-amylase and the effect of wheat seed proteinaceous extracts on its activity

Papilio machaon (Linnaeus) (Lepidoptera: Papilionidae) feeds on different plant species of the family Apiaceae. It also rarely feeds on the Rutaceae family such as rue (Ruta chalepensis) and fennel. In the current study, α-amylase activity of the larval midgut was investigated and characterised. Also, the effect of the wheat seed extracts on the larval midgut was explored. Results showed that the amylase activity was present in the midgut. Gel assays showed that more than one amylase band (three) was present in the larval midgut showing their importance in the insect feeding. Characterisation of the amylase showed that this enzyme was active in a wide range of the pHs. However, optimal pH for the enzyme activity was alkaline pH (pH 8.0). The effect of wheat seed extracts on the amylase activity showed that the insect amylase is highly sensitive to wheat protein extract. These results showed that wheat seed extract have a good potential to be explored more in order to purify its products and these products could be used in IPM programme in order to combat insect pest.