Heterozygote has pearl-like nodes in wings. Wing margins often snipped; venation disturbed. Bristle pattern defective. Eyes small and rough. At 28oC, at least one of these characters always present; at 18oC, phenotype virtually normal. Viability good; fertility of male slightly reduced. Fraction of cells die in all imaginal discs. In wing discs, dead cells surrounded by epithelial cells and produce pearl-like structures in adult wing. RK2.