Petrophila bifascialis, the two-banded petrophila moth, is a moth in the family Crambidae. It was described by Robinson in 1869.[1] It is found in North America, where it has been recorded from Nova Scotia to Florida, west to Texas and north to Ontario.[2]
The wingspan is between 11 and 24 mm. Adults are on wing from late May to September.
The larvae are aquatic, feeding on diatoms and algae.[3]