puparial

Within the puparial shell, tsetse complete the last two larval instars and the pupal stage.

Because puparial cases decay at an extremely slow rate and can be recovered years after the death of an individual, they can become very important to the examination of a corpse.

However, the newly independent tsetse larva simply crawls into the ground, and forms a hard outer shell called the puparial case, in which it completes its morphological transformation into an adult fly.

The importance of the richness of blood to this development can be seen since all tsetse development before it emerges from the puparial case as a full adult occurs without feeding, based only on nutritional resources provided by the female parent.