Bug FAQBluegrass Webworm Moth
Parapediasia teterrellus · Order: Lepidoptera · Family: Crambidae
Also called: Bluegrass Webworm
Source: Wikipedia
The bluegrass webworm moth has a wingspan of about 21 mm. Adults fly from May through October, producing two generations each year. Its caterpillars eat Poa, tall fescue, and sometimes Bermuda grass.
Source: Wikipedia
How to recognize it
Parapediasia teterrellus is a moth in the Crambidae family, known as the bluegrass webworm moth.
Source: Wikipedia
Size
The wingspan is roughly 21 mm.
Source: Wikipedia
Where it lives
In cities it has taken over from other lawn moths such as Tehama bonifatella and Crambus sperryellus.
Source: Wikipedia
What it eats
Larvae feed on Poa species, tall fescue (Festuca arundinacea), and occasionally Bermuda grass (Cynodon dactylon).
Source: Wikipedia
Life cycle
Adults are on the wing from May to October, producing two generations per year.
Source: Wikipedia
When you see it
Adults appear from May through October in two yearly generations.
Source: Wikipedia
Where it is found in the US
Recorded in 42 of 51 states and DC. Most records: Texas, Pennsylvania, Illinois, Maryland, Michigan, New York, Oklahoma, New Jersey.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
Is this moth a problem for my lawn?
Yes, its caterpillars feed on common lawn grasses and can cause damage to turf.
Source: Wikipedia
Same family (Crambidae)
Box Tree MothCydalima perspectalisDamages trees, gardens or crops
Celery Leaftier MothUdea rubigalisDamages trees, gardens or crops
Elegant Grass-veneerMicrocrambus elegans
Hawaiian Beet Webworm MothSpoladea recurvalisDamages trees, gardens or crops
Garden Grass-veneerChrysoteuchia culmellaDamages trees, gardens or crops
Lucerne MothNomophila nearcticaDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Parapediasia_teterrellus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.