Bug FAQAdelphagrotis indeterminata
Adelphagrotis indeterminata · Order: Lepidoptera · Family: Noctuidae
The adult moth has a wingspan of about 30 to 40 millimeters. It occurs from British Columbia down through California. Adults are typically seen flying from August through October, though they can also appear from May to July.
Source: Wikipedia
Size
Wingspan ranges from 30 to 40 mm.
Source: Wikipedia
When you see it
Adults are on wing mainly August to October, with records also in May to July.
Source: Wikipedia
Where it comes from
Found from British Columbia to California.
Source: Wikipedia
Where it is found in the US
Recorded in 5 of 51 states and DC. Most records: California, Oregon, Washington, Montana, Idaho.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Same family (Noctuidae)
Ipsilon Dart MothAgrotis ipsilonDamages trees, gardens or crops
Fall Armyworm MothSpodoptera frugiperdaDamages trees, gardens or crops
Army Cutworm MothEuxoa auxiliarisDamages trees, gardens or crops
Large Yellow UnderwingNoctua pronubaDamages trees, gardens or crops
Silver ΥAutographa gamma
American DaggerAcronicta americanaCan irritate skinSources
- Wikipedia: https://en.wikipedia.org/wiki/Adelphagrotis_indeterminata
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.