| Abstract: | Using light and electron microscopy, the structure of the peritrophic membrane (PM) was studied in females of the biting midge Culicoides punctatus (Mg.) during the process of blood meal digestion. The PM formation occurs in the posterior part of midgut and lasts during the most time of the digestive cycle. The PM precursors are probably not associated with any intracellular granules. The PM consists of two main components: light structural component and dark amorphous matrix, both of which are directly released from the entire microvillar surface. The aggregation of secreted components takes place in the gut lumen to form gel-like multilayered PM up to 6 microns thickness with bundles of microfibrills situated in the PM surface facing the lumen. Similarities and differences of the PM formation in most groups of blood-sucking insects are discussed. |
