Bug FAQWhite Underwing
Catocala relicta · Order: Lepidoptera · Family: Erebidae
Also called: The Relict, White Underwing Moth
The white underwing moth has a wingspan of about 67 to 75 mm. Its caterpillars eat the leaves of birch, hickory, poplars, oaks, willows and related trees.
Source: Wikipedia
How to recognize it
Catocala relicta, called the white underwing, belongs to the moth family Erebidae.
Source: Wikipedia
Size
Adults have a wingspan ranging from 67 mm to 75 mm.
Source: Wikipedia
Where it lives
It is found across southern Canada from Newfoundland to Vancouver Island and extends southward to Missouri and Arizona.
Source: Wikipedia
What it eats
Larvae feed on the leaves of birch, hickory, several poplar species, oaks and willows.
Source: Wikipedia
Life cycle
Adults are active from July through September, producing one generation each year depending on location.
Source: Wikipedia
When you see it
The moth flies during the summer months, typically July to September.
Source: Wikipedia
Where it comes from
Its native range includes southern Canada and parts of the United States such as Missouri and Arizona.
Source: Wikipedia
Lookalikes
It is a member of the Erebidae family, which includes many similarly patterned moths.
Source: Wikipedia
Where it is found in the US
Recorded in 33 of 51 states and DC. Most records: Michigan, Minnesota, Massachusetts, Maine, New York, Vermont, Wisconsin, New Hampshire.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
When can I see adult white underwing moths?
Adults are on the wing from July to September, depending on where you live.
Source: Wikipedia
What trees do the caterpillars eat?
The larvae feed on birch, hickory, poplars, oaks, willows and related species.
Source: Wikipedia
Same family (Erebidae)
Spongy MothLymantria disparDamages trees, gardens or crops
Fall Webworm MothHyphantria cuneaDamages trees, gardens or crops
Brown-tail MothEuproctis chrysorrhoeaCan irritate skin
Isabella Tiger MothPyrrharctia isabella
Virginian Tiger MothSpilosoma virginicaCan irritate skin
Salt Marsh MothEstigmene acreaSources
- Wikipedia: https://en.wikipedia.org/wiki/Catocala_relicta
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.