Bug FAQWilliams' Tiger Moth
Grammia williamsii · Order: Lepidoptera · Family: Erebidae
Williams' tiger moth lives across northern North America, from the Northwest Territories to New England and the northern Great Lakes, and also down the Rockies to Arizona and New Mexico. Its caterpillars eat a wide variety of herbaceous plants and grasses. The species was moved from the genus Grammia to Apantesis along with several related moths.
Source: Wikipedia
What it eats
Larvae feed on many forbs and are probably general feeders on herbaceous plants and grasses.
Source: Wikipedia
Where it is found in the US
Recorded in 15 of 51 states and DC. Most records: Utah, Wyoming, Colorado, Idaho, Montana, Nevada, New Mexico, South Dakota.
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
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/Apantesis_williamsii
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.