Metamorphosis of the Malpighian tubules of Libellula quadrimaculata L.: structure and physiology (Anisoptera: Libellulidae)

The ultrastructural organisation and physiology of the Malpighian tubules of larval and adult stages are described. The main structural difference between larval and adult tubules is the presence of elongate mitochondria inserted into the luminal microvilli of the adults. This correlates with an increase in the basal rate of fluid secretion by the adult tubules, which is some 3-4 times higher than in the larvae.