The effect of cereal seed extracts on amylase activity of the rose sawfly, Arge rosae Linnaeus (Hymenoptera: Argidae)

Abstract

The sawfly, Arge rosae Linnaeus (Hymenoptera: Argidae) is a serious pest of rose plants in a vast area of the world including Iran. Pesticides are applied in order to control in areas where infestation is high. So, there is a need for more environmentally benign alternatives to control this insect pest in urban areas. Therefore, the aim of the current study was to study the effect of cereal seed proteinaceous extracts including wheat and triticale on the insect α-amylase. Wheat and triticale seed proteins as well as fourth instars larvae α-amylase were extracted. The results showed that there are two different α-amylase isoenzymes in the insect gut, one major band and the other minor band, which had optimal activity at alkaline pH (pH 8.0). The effect of five concentrations including 0.42, 0.21, 0.105, 0.05 and 0.025 mg ml−1 of each seed extract was tested on α-amylase activity of the larvae gut. At the highest concentration (0.42 mg ml−1), wheat seed extract caused 74% inhibition of the enzyme activity while triticale seed extract inhibited 62% enzyme activity. Experiments proved that seed proteinaceous extract affected the enzyme activity in a pH-dependant manner.