dare⁴/dare⁵ larvae show a delay in pupariation; in synchronous cultures of larvae, only 34% of dare⁴/dare⁵ larvae pupariate during the 48 hour period following the pupariation of the first control larva (100% of the control larvae pupariate during this period). This defect is substantially rescued by feeding the larvae 20-hydroxyecdysone. Most dare⁴/dare⁵ and dare⁴/dare³⁴ larvae pupariate (despite the delay in dare⁴/dare⁵ animals), but then undergo premature lethality, mostly dying late in metamorphosis or early in adult life. The adults show an extreme behavioural phenotype; they are unable to stand, lying on the substratum with legs and wings twitching. Striking degeneration is seen in the adult nervous system; large vacuoles are seen in a variety of brain regions including the antennal lobes, the optic lobes, the ellipsoid body and the fan-shaped body of the central complex and in the thoracic nervous system. The vacuoles in the optic lobes appear after optic lobe assembly is complete or largely complete, and enlarge as the animal ages. Other brain regions and the thoracic nervous system also appear to assemble normally and then undergo degeneration. The earliest evidence of vacuoles is seen in the ellipsoid body and fan-shaped body, where degeneration first becomes apparent during the late pupal stages. Gross degeneration is not seen in the antenna.

Defect in pupariation that can be partially rescued by ecdysone feeding.