A morphological study on the midgut and Malpighian tubules of Oxythyrea funesta (Poda, 1761) (Coleoptera: Scarabaeidae) using light and scanning electron microscopy

In insects, the midgut is the primary organ where chemical digestion and nutrient absorption occur, while the Malpighian tubules play a critical role in removing metabolic waste and maintaining osmoregulation, making them vital to the functioning of the digestive and excretory systems. Therefore, in this study, the morphological structure of the midgut and Malpighian tubules of Oxythyrea funesta (Poda, 1761) (Coleoptera: Scarabaeidae) was examined using stereo, light, and electron microscopes. According to this study’s findings, the digestive system of O. funesta consists of three sections: the midgut, located between them, is the longest and extends as a straight, tube-like structure from the foregut, forming two annular structures toward the hindgut. The midgut is characterized by a single-layered cylindrical epithelium, a thin muscle layer, and a peritrophic membrane in the lumen; the epithelial cells exhibit apocrine secretion, and regenerative cells at the base; in SEM images of the midgut, secretory vesicles in the lumen and short microvilli extending from the apical surface of the epithelial cells are discernible. The Malpighian tubules, on the other hand, are a pair of long, tubular structures with flat surfaces that extend from the midgut to the hindgut. Light and SEM examinations of these tubules reveal microvilli extending from the apical surface of a single-layered cuboidal epithelium with round nuclei. This study aims to characterize the midgut and Malpighian tubules of O. funesta , supporting comparative studies in Scarabaeidae and future development of selective pest management strategies.