Induction of some digestive enzymes in the midgut of the sandfly Phlebotomus langeroni after sugar and blood meals.

Changes associated with blood and sugar meal digestion in the sandfly, Phlebotomus langeroni were characterized. Different types of sugars: sucrose, glucose, melibiose, cellobiose, lactose, starch, fig fruits, honey dew and a mixture of sucrose and sugar sources were used for the sandfly feeding. Activities of glycosidases and proteases in the sandfly guts after blood and sugar meals were determined using the endpoint method. The results showed that glycosidases (alpha-glycosidase, beta-glycosidase, alpha-galactosidase, and beta-galactosidase) are present in the sandfly midguts. No activities of the glycosidases (alpha-mannosidase and alpha-amylase) were detected in the sandfly gut. Proteases: trypsin and aminopeptidase showed activities in the sandfly midguts. It is concluded that the midgut glycosidase may play an important role in the vector-parasite interaction. Trypsin and aminopeptidase induction after a blood meal is controlled by a secretogogue mechanism which indirectly influences the outcome of the Leishmania parasite infection.