stw³/Df(2R)BSC696 adults display pigmentation defect - their bristles and wings lose the characteristic dark color and appear yellow, although the pigmentation of abdominal tergites remains largely unaffected.

Larval mouth part colour: straw at basal prongs; classifiable in living larva.

Wings thin and buckled; hairs on wing cells incompletely chitinized.

Body colour: yellowish with pronounced dark trident; hairs, bristles, wings and wing veins straw yellow. Puparium colour: noticeably lighter than wild type. Waddington (1940) found that irradiation of stw³ homozygote 2 days before eclosion produces reverse mutations that appear as single wild-type wing hairs.