Homozygous larvae grow until the end of the third larval instar, but 50% do not form a puparium and fail to pupariate (showing no spiracle eversion, body shortening or pigmentation). The remaining 50% do undergo puparium formation, showing spiracle eversion, gas bubble formation and the moulting associated with pupation, but then they die. Homozygotes that undergo puparium formation show normal chromosome puffing at the time of spiracle eversion (0 hour prepupae), 4 hour prepupae show small differences in the size of the puffs at 66B and 85D1-2 compared to wild type and 8 hour prepupae show small differences in the size of the puffs at 34A5-6, 63E1-3, 73EF and 93F9-10 compared to wild type. Dramatic differences from wild type are seen in 10 hour prepupae; at the time of the late prepupal wave nearly all of the ecdysone inducible puffs that normally appear in wild-type animals either fail to appear or are significantly smaller than normal, while several puffs which normally disappear in 10 hour prepupae are still active in homozygotes (34A5-6, 52C4-7, 63D1-2, 63E1-3, 63E1-3', 69A1-3, 75CD and 85D1-2).

The cells of the salivary gland imaginal ring are reduced in number or absent in homozygous larvae.