Exposure of mutant flies to 17^oC between 12-24, 48-60 or 98-108 hours of development results in a substantial increase in the number of wing abnormalities. Non-differentiated imaginal discs, discs lacking the notum region and discs with a duplication of wing-forming regions are seen. Exposure of mutant flies to 17^oC between 12-24, 48-60 or 98-108 hours of development results in a substantial increase in the number of wing abnormalities. Non-differentiated imaginal discs, discs lacking the notum region and discs with a duplication of wing-forming regions are seen.

Heterozygotes have reduced, monstrously formed eyes, often with a bundle of bristles in the centre of a caverna funning through the facets. The wing often shows notching or blistering, and is sometimes reduced to a ribbon of material. Occasionally the wing is converted to a scutellum-like element with bristles and hairs. Halteres may be completely or partially reduced. Occasionally the legs are deformed, with the segments shortened and bulged. The phenotype is incompletely penetrant, with a lower penetrance at higher temperatures.