Bug FAQIlia Underwing
Catocala ilia · Order: Lepidoptera · Family: Erebidae
Also called: Ilia Underwing Moth
The Ilia Underwing moth has a wingspan of about 65 to 82 mm and shows a distinctive white-circled spot on each forewing. Its bright underwings range from light orange to deep red, and the caterpillars feed on various oak species.
Source: Wikipedia
How to recognize it
A forewing spot surrounded by a clear white circle sets this species apart from other Catocala moths.
Source: Wikipedia
Size
The adult’s wingspan measures between 65 and 82 mm.
Source: Wikipedia
Where it lives
It lives in the eastern United States and southern Canada, while the subspecies C. ilia zoe occurs in California and Arizona.
Source: Wikipedia
What it eats
Caterpillars feed on oak trees, including black, burr, red, and white oaks.
Source: Wikipedia
Life cycle
Adults are on the wing from June through September, depending on location.
Source: Wikipedia
When you see it
Flight season runs from early summer to early fall, varying by region.
Source: Wikipedia
Where it comes from
Its native range includes the eastern U.S. and southern Canada, with a western subspecies found in California and Arizona.
Source: Wikipedia
Lookalikes
The white-circled forewing spot helps distinguish it from similar underwing moths.
Source: Wikipedia
Where it is found in the US
Recorded in 46 of 51 states and DC. Most records: Texas, Massachusetts, California, Connecticut, Pennsylvania, Michigan, Virginia, Ohio.
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 are Ilia Underwing moths active?
They fly from June to September, with exact timing depending on where they live.
Source: Wikipedia
What do Ilia Underwing caterpillars eat?
The larvae feed on oak leaves, including several oak species.
Source: Wikipedia
How can I tell an Ilia Underwing apart from other moths?
Look for a distinct white-ringed spot on each forewing; the underwings are orange to deep red.
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_ilia
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.