Adult lethal.

Homozygotes frequently fail to escape from the puparium and die during eclosion. This mortality increases under desiccated conditions and decreases under humid conditions. Homozygous flies are more sensitive to desiccation than wild-type; all flies die within 3 hours under desiccated conditions without a water supply, in contrast to wild-type where 50% survive for more than 15 hours under the same conditions. Flies survive longer in a moist environment without a water supply than in a desiccated environment. Homozygous adult flies (both alive and dead) have a higher rate of water loss than wild-type flies. The time course of retention of ingested sucrose is similar to wild-type. Homozygous flies drink more water than wild-type flies. The survival time (in a desiccated environment) of mosaic flies containing both wild-type and pch³ mutant cuticle is prolonged in proportion to the amount of wild-type cuticle present. There are no significant qualitative or quantitative differences in the cuticular hydrocarbons of pch³ and wild-type flies. Homozygous larvae and pupae show no significant difference in body weight loss compared to wild-type in a desiccated environment.