ap^78j/ap⁵⁴ flies show wing margin and size reductions characteristic of weak ap mutations.

Temperature-sensitive allele. Histolysis of the larval fat body is essentially normal in homozygous females kept at the restrictive temperature (25^oC).

When raised at 22^oC, wing and haltere phenotype approaches wild type except for missing patches of triple-row bristles and posterior wing margin. When raised at higher temperatures, phenotype becomes more severe and resembles ap⁴ at 29^oC. Two nonoverlapping temperature-sensitive periods in development, one in late-second to middle-third instar for wing and haltere deficiency phenotype and the other during the first day of pupal development for precocious adult death and nonvitellogenesis phenotype. Wing discs of heat-pulsed larvae failed to exhibit cell death by trypan blue exclusion.