Absence of humeral bristles in hemizygotes.

Homozygous viable and fertile. Sometimes the humeral bristles are absent, at 18^oC the posterior supraalar bristle is missing.

Homozygotes normal and viable, hemizygotes have only 50% humeral bristles, other bristles missing with frequency of 5%.

Homozygous viable.

viable and of normal phenotype in both homozygous and heterozygous condition heterozygotes for feo¹² and any lethal allele except feo¹ or for a deficiency for feo show irregularly missing bristles, especially humerals;