Studies On Digestive System Structure And Function Of Locusta Migratoria Menilensis

In this thesis, the structure of salivary glands and alimentary canal of Locusta migratoria menilensis were observed by anatomical microscope, optical microscope and scanning electron microscopy. The results show that the salivary glands of Locust migratoria menilensis were grape-like, and gathered into acinars, which include zymogenic cells, parietal cells, sheath cells and tubules.After the determination, salivary glands contain amylase, protein enzymes, and cellulase, and their activities are lower than them in the midgut. Therefore, salivary glands have the role of lubrication and assisted digestion of food. Alimentary canal contains foregut, midgut and hindgut. There are esophagus, crop, proventriculu and cardia in the foregut and in which there are teeth that are backward for stiring and pushing down the food, teeth is longest in the esophagus to prevent food refluxing. Cardia has six Y-shaped bulges, and its teeth are perpendicular to the intestinal wall, and its role is to regulate the speed of food moving down. Midgut is the main place for food digestion and absorption, for microvilli to expand the surface area of absorption, and amylase, protein enzymes, cellulase, pectinase, maltoseenzymes and lipase, their activities are higher than them in the salivary glands. There are pylorus, cardia, colon, rectum and anal region in the hindgut. Pylorus has12raised parts which have teeth and the teeth are toward to control the speed of food down. The surface of Ileum has sieve pitting for food dehydration. Colon has more teeth pointing to the rear to promoting the digested food into the rectum. Rectum has six toothless rectal pads and sieve pitting. The teeth are on the inner wall of rectal, which is perpendicular to the vertical axis of the digestive tract, its role is to squeeze the food and dehydrate to feces. Multiple columns longitudinal muscle is in the anal area, and the spherical bulge on the end. In this study, the structure of the salivary glands and the digestive tract of Locusta migratoria menilensis have been discussed through three levels by various means and methods. Our study is not only providing a basis for insect physiology, biochemistry and insect classification, but also providing a basis for the protection of economic insects, the development of new drugs for anti-locust and the determination of the target sites.