Bug FAQTwo-banded Petrophila
Petrophila bifascialis · Order: Lepidoptera · Family: Crambidae
The two-banded petrophila moth (Petrophila bifascialis) belongs to the family Crambidae. Adults have a wingspan of about 11 to 24 mm and fly from late May through September. It lives across North America, from Nova Scotia and Ontario down to Florida and west to Texas, and its aquatic larvae feed on diatoms and algae.
Source: Wikipedia
How to recognize it
Petrophila bifascialis is a moth in the family Crambidae.
Source: Wikipedia
Size
The wingspan ranges between 11 and 24 mm.
Source: Wikipedia
What it eats
Aquatic larvae eat diatoms and algae.
Source: Wikipedia
Life cycle
Adults are on the wing from late May to September.
Source: Wikipedia
When you see it
Flight period extends from late May through September.
Source: Wikipedia
Where it comes from
Its range includes eastern Canada and the eastern United States.
Source: Wikipedia
Lookalikes
It is a member of the Crambidae family, which includes many similar moths.
Source: Wikipedia
Where it is found in the US
Recorded in 23 of 51 states and DC. Most records: Texas, Maryland, Virginia, Ohio, Michigan, Illinois, Indiana, Alabama.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Same family (Crambidae)
Box Tree MothCydalima perspectalisDamages trees, gardens or crops
Celery Leaftier MothUdea rubigalisDamages trees, gardens or crops
Elegant Grass-veneerMicrocrambus elegans
Hawaiian Beet Webworm MothSpoladea recurvalisDamages trees, gardens or crops
Garden Grass-veneerChrysoteuchia culmellaDamages trees, gardens or crops
Bluegrass Webworm MothParapediasia teterrellusDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Petrophila_bifascialis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.