Bug FAQSweetfern Underwing Moth
Catocala antinympha · Order: Lepidoptera · Family: Erebidae
Also called: Sweetfern Underwing
The Sweetfern Underwing Moth has a wingspan of about 45 to 55 mm. Adults fly from July through September. Its caterpillars feed only on sweetfern (Comptonia peregrina).
Source: Wikipedia
Size
Wings measure roughly 45 to 55 mm across.
Source: Wikipedia
What it eats
The larvae eat the leaves of sweetfern, Comptonia peregrina.
Source: Wikipedia
Life cycle
There is one generation each year.
Source: Wikipedia
When you see it
Adults are on the wing from July through September.
Source: Wikipedia
Where it comes from
Its native range covers the same eastern Canadian provinces and US states listed for its habitat.
Source: Wikipedia
Where it is found in the US
Recorded in 19 of 51 states and DC. Most records: Massachusetts, Michigan, New York, Maine, Connecticut, Wisconsin, New Jersey, New Hampshire.
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
Questions people ask
When can I see adult Sweetfern Underwing Moths?
Adults are active from July to September.
Source: Wikipedia
What do the caterpillars eat?
The caterpillars feed on sweetfern (Comptonia peregrina).
Source: Wikipedia
How many generations are produced each year?
The species has one generation per year.
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_antinympha
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.