This study provides the first detailed anatomical and histological examination of the alimentary canal in the final instar larva of Deudorix isocrates (Fab.), a topic previously unexplored. The alimentary canal is divided into three main sections: the foregut, the midgut, and the hindgut. The foregut consists of the buccal cavity, esophagus, pharynx, and crop. The buccal cavity, pharynx, and esophagus walls are lined with cuboidal epithelium, forming 6 longitudinal folds. The posterior pharynx is characterized by longitudinal ridges and backwardly directed bristles. The intima in this area is thin, with numerous folds of squamous epithelium, and the musculature is minimal. A stomodaeal valve with distinct histological features is present at the transition from the foregut. The midgut wall is made of simple columnar epithelium, containing scattered goblet cells and single regenerative cells, and is lined with a peritrophic membrane. The midgut also has thin musculature, consisting of an inner circular muscle layer and an outer longitudinal muscle layer. The hindgut, which includes the pylorus, colon, and rectum, is lined with cuboidal epithelium, while the ileum is lined with squamous epithelium. The intima in the hindgut is thinner than in the foregut, with patches of spines located near the posterior pylorus. The rectum is associated with the formation of the cryptonephridial system.
