Mutants appear to progress normally through embryogenesis, but larval development proceeds much more slowly than normal, with third instar larvae living for up to 21 days before dying without pupation. The brain, ring gland, salivary glands and imaginal discs are reduced in size in homozygous larvae compared to controls. Mutant larval neuroblasts have abnormally shaped nuclei, though mitotic figures, which are seen even in 20 day old larvae, are normal in appearance. Melanotic masses appear in the haemolymph of the mutant larvae during the lengthened third instar phase, increasing in size and number over time.

There is a dramatic increase in cell death in the mutant third instar larval neuroblasts as they age. An increase in cell death is also seen in homozygous clones in larval imaginal discs.

Autophagy is seen in the fat body of fed mutant third instar larvae, in contrast to wild type.

The triglyceride:protein ratio is reduced in mutant third instar larvae compared to wild type.

Mutant larvae fail to encapsulate eggs when parasitised by the avirulent L. boulardi wasp strain G486 (no melanisation is seen). Plasmatocytes and lamellocytes are absent from the capsule surrounding the egg.