Larval growth arrest, L1 stage. 60% survive until 4 days after hatching. 10% survive until 9 days after hatching. DNA replication ceases. Mutant clones induced in the wing disc induced at 36 hours after hatching are reduced in size, though those induced at 42 hours are close to wild type in size. Adults in which clones have been induced show large cuts in the wing. Mutant clones in the eye produce very few cells, though mutant clones in discs show increased cell death, suggesting mutant cells do not survive.