Glycerol accumulation in developmentally arrested pupae of Papilio machaon obtained by brain removal

Brains were removed from non-diapausing pupae of Papilio machaon within 24 hr after pupation. The developmentally arrested pupae were examined for glycerol metabolism by comparison with naturally diapausing pupae. The decerebrate non-diapausing pupae accumulated appreciable amounts of glycerol (13.0 mg/ml haemolymph) during exposure to 5°C for 2 months. However, this amount was considerably lower than that accumulated in the naturally diapausing pupae (24.5 mg/ml) under the same conditions. A difference was also observed in the initial level of the glycogen in the fat body. The naturally diapausing pupae contained about 105 mg/g glycogen, while the decerebrate non-diapausing pupae contained only about 70 mg/g, one day after pupation.