Homozygotes have abnormal tarsi. Most frequently the second, third and fourth tarsi are lost and the first tarsus is shorter than in wild-type flies. Less frequently, the fifth tarsus arises from the tibia. Other phenotypes seen at low frequency include the fifth tarsus surrounded by three globular appendices which arise from the tibia, and almost wild-type first and fifth tarsi. More than 50% of homozygous adults die in the first day after eclosion. Pre-adult survival is also decreased, varying between 20% to 100%.

Homozygotes exhibit different degrees of tarsal aplasia; most frequently second, third and fourth tarsal joints missing; less frequently the fifth tarsal joint arises from tibia; often a rudimentary tarsal appendage arises from tibia or the fifth tarsal joint. Adult and preadult survival reduced; more than 50% of imagos die during the first day.