Bug FAQRiver Birch Dagger
Acronicta betulae · Order: Lepidoptera · Family: Noctuidae
Also called: Birch Dagger, birch dagger moth
Source: Wikipedia
The birch dagger moth has a wingspan of about 35 to 40 mm. It lives from New Hampshire down to Florida, west to Texas and north to Wisconsin. Adults appear in two generations, flying from March to May and again from August to September.
Source: Wikipedia
How to recognize it
Acronicta betulae is a moth in the Noctuidae family, commonly called the birch dagger moth.
Source: Wikipedia
Size
Its wingspan measures roughly 35 to 40 mm (1.4 to 1.6 in).
Source: Wikipedia
What it eats
The caterpillars feed on birch leaves, especially those of river birch (Betula nigra).
Source: Wikipedia
Life cycle
Adults are on the wing in two periods: March-May and August-September, representing two generations per year.
Source: Wikipedia
When you see it
You’ll see adults flying from early spring to late spring and again in late summer to early fall.
Source: Wikipedia
Where it comes from
Its native range includes the eastern United States from New Hampshire down to Florida and west to Texas, reaching up to Wisconsin.
Source: Wikipedia
Where it is found in the US
Recorded in 35 of 51 states and DC. Most records: Alabama, North Carolina, Virginia, Maryland, Mississippi, Georgia, Indiana, Texas.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
When are birch dagger moths active?
Adults fly from March to May and again from August to September.
Source: Wikipedia
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/Acronicta_betulae
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.