Bug FAQLarge Ruby Tiger Moth
Phragmatobia assimilans · Order: Lepidoptera · Family: Erebidae
The large ruby tiger moth has forewings 14 to 19 mm long and shows dusty orange-brown wings with dark grey lines and a discal spot, while its hindwings are pinkish-red with a black edge and dark veins. Adults fly from late spring through August, producing one generation each year, and the caterpillars eat a variety of herbaceous plants and low woody shrubs.
Source: Wikipedia
Size
The forewing length ranges from 14 to 19 mm.
Source: Wikipedia
Where it lives
It inhabits open meadows and moist forest areas.
Source: Wikipedia
Life cycle
Adults are on the wing from late spring to August, producing one generation per year.
Source: Wikipedia
When you see it
Adults are active from late spring through August.
Source: Wikipedia
Where it is found in the US
Recorded in 20 of 51 states and DC. Most records: Massachusetts, Michigan, Connecticut, Minnesota, New Hampshire, Vermont, Wyoming, New York.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
When are large ruby tiger moths active?
Adults fly from late spring until August, with one generation each year.
Source: Wikipedia
What do the caterpillars eat?
The larvae feed on a range of herbaceous plants and low woody hardwood shrubs.
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 acreaDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Phragmatobia_assimilans
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-25 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-25.