Effects of ecdysone on the in vivo growth of wing disks of Calliphora erythrocephala

The normal growth of wing disks is compared with the growth of disks from larvae surgically deprived of ring glands at 5 or 6 days and later unable to form a puparium. During the third instar, the growth of wing disks is constant. It seems to slow down after puparium formation. Twelve days after the ablation of the ring gland, the volume of the wing disks is no different from the volume of the wing disks for 6-day-old larvae. Ecdysone is needed for the growth of imaginal wing disks but the ecdysone peak does not accelerate growth.