Approximately 9% of larvae form a puparium with a long delay after reaching the mature size, while the rest die as larvae. The puparia are bloated with hemolymph. Tanning and sclerotisation of the puparial cuticle is uneven and imperfect, and the cuticle does not prevent evaporation of internal water. A wild-type ring gland implanted into mutant larvae significantly accelerates puparium formation.