The majority (61%) of daw^δ2 mutants die as white prepupae or as pharate adults and do not eclose. When reared at low density on nutritive agar plates, 15% eclose but most die shortly after eclosion. Rare escapers are fertile.

Motorneuron pathfinding is disrupted in these embryos as although the ISNb and SNa axons exit the ventral nerve cord correctly and extend into their target field, they fail to advance far enough to innervate the appropriate muscle. The ISNb axons commonly stall at muscle 6 and fail to form synapses on muscles 12 and 13, or reach muscle 12 but are unable to form a synapse. The SNa usually extends into the target muscle but frequently exhibits the loss of one or both branches. In embryos from daw³/daw³ mothers mated to daw^δ2/daw^δ2 fathers, the incidence of ISNb and SNa defects is higher than in zygotic nulls.