The effects of chilling and integumentary injury on carbohydrate and lipid metabolism in diapause and non-diapause pupae of Manduca sexta

Abstract

1. 1. The effects of chilling and integumentary injury on carbohydrate and lipid metabolism in diapause and non-diapause pupae of Manduca sexta were studied. 2. 2. Chilling only affected carbohydrate metabolism in non-diapause pupae. Active fat body glycogen phosphorylase increased from 5 to 80% ( P < 0.001) and a decrease of the fat body glycogen content ( P < 0.025) was found within 2 hr. Haemolymph lipid concentrations were unaffected in either type of pupae. 3. 3. Integumentary injury did not cause changes in carbohydrate metabolism, but diapause pupae exhibited a slightly increased haemolymph lipid level ( P < 0.05). 4. 4. In Hyalophora cecropia chilling caused an activation of fat body glycogen phosphorylase within 24 hr ( P < 0.001); integumentary injury did not. Haemolymph lipid concentrations were significantly increased only 2 hr after chilling ( P < 0.025); again experimental injury exhibited no effect.