The hormonal control of diuresis in the cabbage white butterfly Pieris brassicae.

The diuresis which follows the pupal-adult ecdysis of Pieris brassicae is hormonally controlled. Use of the isolated Malpighian tubules as a bioassay shows the presence of substantial diuretic activity in homogenates of the brain and corpus cardiacum-corpus allatum complex. The hormone is probably produced in the brain and released from a storage site in the corpora cardiaca. The tubules of the butterfly are maximally responsive to the diuretic hormone at the time of eclosion.