Bug FAQWoolly Grass-veneer Moth
Thaumatopsis pexellus · Order: Lepidoptera · Family: Crambidae
The woolly grass-veneer moth (Thaumatopsis pexellus) is a Crambidae with a wingspan of about 21 to 32 mm. It lives in grasslands throughout most of North America and its larvae feed on various grasses. Adults are on the wing from July to early September.
Source: Wikipedia
How to recognize it
Thaumatopsis pexellus, known as the woolly grass-veneer, belongs to the family Crambidae.
Source: Wikipedia
Size
The moth’s wingspan ranges from 21 to 32 mm.
Source: Wikipedia
Where it lives
It inhabits grassland environments.
Source: Wikipedia
What it eats
Larvae feed on a variety of grasses.
Source: Wikipedia
Life cycle
Adults are active from July through early September in most of the range.
Source: Wikipedia
When you see it
The flight period spans July to early September.
Source: Wikipedia
Where it comes from
It is found across most of North America.
Source: Wikipedia
Where it is found in the US
Recorded in 30 of 51 states and DC. Most records: Montana, Minnesota, Colorado, Nebraska, Texas, Michigan, Oklahoma, 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
Questions people ask
When are adult woolly grass-veneer moths active?
Adults fly from July until early September.
Source: Wikipedia
Where does this moth live?
It lives in grassland habitats across most of North America.
Source: Wikipedia
Same family (Crambidae)
Box Tree MothCydalima perspectalisDamages trees, gardens or crops
Celery Leaftier MothUdea rubigalis
Elegant Grass-veneerMicrocrambus elegans
Hawaiian Beet Webworm MothSpoladea recurvalisDamages trees, gardens or crops
Garden Grass-veneerChrysoteuchia culmellaDamages trees, gardens or crops
Bluegrass Webworm MothParapediasia teterrellusDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Thaumatopsis_pexellus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-25 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-25.