A5-A8 are transformed to A4, females lack genitalia, and there is a weak haploinsufficient transformation of A5-A8. Parasegments 10-13 are transformed to parasegment 9 in embryos.
Heterozygous males have a 7th tergite, there is loss of pigment in the anterior of the 5th tergite, and the 6th sternite has bristles.
Embryos hemizygous for Abd-BS9 have an Abd-B mutant phenotype: denticle belts of parasegments 10-13 resemble that of parasegment 9. The posterior spiracles, dorsal spinule patch, and a sense organ of parasegment 14 are missing. The denticle belt of parasegment 13 is separated from the anal plates by an enlarged bald region.
Fails to complement iab-5 and iab-6 alleles.