Ultrastructure of digestive canal of graphosoma lineatum (Linneaus, 1758) (Heteroptera: Pentatomidae)

In this study, ultrastructure of digestive canal of Graphosoma lineatum (Linneaus, 1758) (Heteroptera: Pentatomidae) was examined with the use of light microscope and scanning electron microscope (SEM). Digestive canal of G. lineatum consists of three distinct regions: Foregut, midgut and hindgut. Foregut and hindgut are very short. Midgut is longer and differentiated into three distinct portions: Anterior, median, posterior. Anterior region is similar to a wide elongated sac. Median region is narrower and tubular in shape. Posterior region is a short dilated portion. There are two pairs of Malpighian tubules at the junction of midgut and hindgut.The alimentary canal of G. lineatum is generally similar to other Heteroptera species? digestive system. The epithelial cells of foregut are cubically arranged as a single layer. According to SEM images, foregut is surrounded by a layer of longitudinal muscle and inner surface is formed by cell groups which are located over a folded basal lamina. Midgut surface is surrounded by a layer of inner circular and outer longitudinal muscles. Inner surface of midgut is formed by a single layer of cylindrical cells. Hindgut has an extremely thin epithelial cell layer. The surface of cells in hindgut does not contain microvillus, but they are wrinkled.Malpighian tubules are consisting of single layer cubical epithelium cells. Apical surface of cells is covered with microvillus. In contrary to proximal parts of Malpighian tubules which are smooth, distal parts are arranged as clustered beads. The surface of Malpighian tubules is smooth. Epithelial cells of Malpighian tubules have rounded granules in their cytoplasm.