Most homozygous embryos hatch and develop into pupae, and some become pharate adults which die without eclosion. Rarely, adult escapers are seen, which are flightless. Morphological defects are seen in the indirect flight muscles (IFMs) of homozygous late pupae; myofilaments are normally packed in the centre of the muscles but the lattice structure is loose around the periphery near Z-discs. M-lines form normally.