Deletion of approximately 1.5kb beginning in the 5' end of the P{lacZ} and extending to within the third exon, removing all exon 2 and part of exon 3 including the entire homeodomain sequence.
The cerebral branch of the tracheal system of the embryo is absent. Occasional ectopic branches appear in the first metamere. The cerebral anastomosis is also absent. Ganglionic branches extend only partially and fail to penetrate the CNS. Under uncrowded conditions 3-5% of mutants eclose to adulthood. These escapers show an upheld wing phenotype.