Effect of neutral red on carbohydrate levels in the tobacco hornworm, Manduca sexta (L.) (Lepidoptera: Sphingidae)☆

Abstract 1. 1. The effect of acute hemocoel injection (100 mg/kg) of neutral red on hemolymph trehalose and fat body glycogen has been examined in the tobacco hornworm, Manduca sexta (L.). 2. 2. Neutral red caused a 70% increase in hemolymph sugar 6 hr after injection. 3. 3. Hypertrehalosemia persisted for 18 hr and was followed by hypotrehalosemia. 4. 4. Fat body glycogen was unchanged up to 12 hr. 5. 5. A 60% glycogenolytic response was observed 48 hr after injection.