Homozygotes generally have normal wing phenotypes but can have slightly extended wings. The dorsal longitudinal muscles (DLMs) have degenerated fibres (degeneration occurs a few hours before eclosion) that are split in the posterior end. The dorsoventral muscles (DVMs) appear normal. Where degeneration occurs, no banding pattern of the myofibrils is seen. Homozygotes with expanded wings have weak or moderate flight ability, while most of those homozygotes with normal wings are have normal flight ability.