The vast majority of homozygous animals show a lethal phenotype before head sac eversion. Occasionally 5 to 6 days after pupariation a red eye colouration is visible within an abnormal head sac of animals which otherwise resemble late prepupae. In most cases necroses appear at one third body length and increase with time.
Lethality occurs during third instar larval or pupal stages. Mutants do not show any visible disc abnormalities.
I. Kiss.