A duplication has been made by FLPase mediate recombination between the two insertions P{HomingPigeon.FRT}UbxHC166D.Scer\FRT and P{HomingPigeon.FRT}UbxHC71-1.Scer\FRT. A single intact P{HomingPigeon.FRT} remains.
About 2% of individuals show a reduction of the notum and malformation of the wings. When heterozygous with Ubx1, Ubx9.22, Ubxbxd-100 or Df(3R)P2 the notum reduction phenotype is much more penetrant and severe. These animals also show an enlargement of the haltere, with anterior bristles, characteristic of a weak bx transformation.