Bug FAQSod Webworm Moth
Pediasia trisecta · Order: Lepidoptera · Family: Crambidae
Also called: Greater Sod Webworm, Sod Webworm
Source: Wikipedia
The large sod webworm has a wingspan of about 23 to 33 mm. It lives in the United States and southern Canada, and adults are seen from May through October. Adults sip dew, while the caterpillars feed on various grass species.
Source: Wikipedia
How to recognize it
Pediasia trisecta, known as the large sod webworm, belongs to the moth family Crambidae.
Source: Wikipedia
Size
Its wingspan ranges from 23 to 33 mm.
Source: Wikipedia
What it eats
Adult moths feed only on dew. Larvae eat a variety of grass species (Poaceae).
Source: Wikipedia
Life cycle
Adults are on the wing from May to October.
Source: Wikipedia
When you see it
They are active during the months of May through October.
Source: Wikipedia
Where it comes from
Its native range includes the United States and southern Canada.
Source: Wikipedia
Where it is found in the US
Recorded in 44 of 51 states and DC. Most records: Michigan, Pennsylvania, Illinois, Minnesota, Wisconsin, Connecticut, New York, Massachusetts.
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
What do the larvae eat?
The caterpillars feed on various grass species in the Poaceae family.
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
Bluegrass Webworm MothParapediasia teterrellusDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Pediasia_trisecta
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.