Homozygous females are slightly fertile, and lay 63-95% as many eggs as wild-type. The endochorion is essentially wild-type, and the respiratory appendages are abnormal.
Mature follicles of homozygous females have no defects in the endochorion but have defective respiratory appendages.
Germ line clonal analysis shows that fs(1)de1f is germ line-dependent.