ecd² homozygotes, ecd²/Df(3L)R-R2 and ecd²/ecd^l(3)23 animals die after a prolonged L2. Most ecd¹/ecd² animals die during the L2/L3 molt, displaying typical molting defects such as double mouth hooks, but some survive into L3. Larval Lethality in ecd² homozygotes is not rescued by feeding with 20-hydroxyecdysone (50 μg/ml or 250 μg/ml). ecd² homozygous somatic clones induced at 24-36 hours after egg laying do not survive in wing or eye discs to late third instar. The resulting adults appear normal. However, such clones induced at the onset of the third instar do survive in late third instar eye discs. ecd² homozygous clones in the ovary cause egg chamber fusions, typically producing egg chambers with double the normal number of germ cells. Egg chambers in which all germ cells are part of ecd² homozygous germ-line clones arrest development early in oogenesis, showing degeneration of nurse cells, resulting in female sterility.

Hemizygous larvae die 48 to 72 hours after hatching, failing to survive the moult to the second instar stage. ecd¹/ecd² transheterozygotes die as they moult to the third larval instar; most die during ecdysis, with the old cuticle often remaining attached to the posterior end of the abdomen. The number of macrochaetae on the thorax is reduced in ecd¹/ecd² flies kept at 29^oC in the hours that follow prepupal formation.

Temperature upshift at egg-laying or early third instar caused larval lethality. Temperature upshift at puparium formation causes pharate adult lethality.

nonconditional allele