Spatial organization of digestive processes in an adult carabid beetle, Scaphinotus marginatus (Coleoptera: Carabidae)

Abstract

Adults of Scaphinotus marginatus liquefy and lubricate food prior to ingestion by the application of a fluid containing trypsin and chymotrypsin. This fluid is unlikely to be a salivary secretion because carabids, like other coleopterans, lack well-developed salivary glands. Results indicate that the midgut secretes these enzymes but that they are stored in the crop from which they are regurgitated onto the food prior to feeding. After ingestion, food is stored and digested in the crop. The structure of a proventricular valve in relation to regurgitation and crop storage is discussed.