Bug FAQArmy Cutworm Moth
Euxoa auxiliaris · Order: Lepidoptera · Family: Noctuidae
Also called: army cutworm
Source: Wikipedia
The army cutworm moth is common in western North America and migrates seasonally through many western states. Its larvae feed on emerging small grains, alfalfa, canola and can strip leaves from native shrubs like sagebrush and four-wing saltbush.
Source: Wikipedia
How to recognize it
Adult moths are known as miller moths because their wing scales easily come off.
Source: Wikipedia
Where it lives
Larvae live in areas where cheatgrass and mustards grow, causing die-offs of cheatgrass and defoliating native shrubs.
Source: Wikipedia
What it eats
Larvae eat emerging small grains, alfalfa and canola on the Great Plains and in southern Canada. They also consume cheatgrass and mustards, leading to cheatgrass die-offs.
Source: Wikipedia
Life cycle
There is one generation each year.
Source: Wikipedia
When you see it
They return to low elevations in the fall as weather cools, but in smaller numbers.
Source: Wikipedia
Where it comes from
The species is found across western North America.
Source: Wikipedia
Lookalikes
Adults are grouped with other abundant moths that shed wing scales, all called miller moths.
Source: Wikipedia
Where it is found in the US
Recorded in 22 of 51 states and DC. Most records: Colorado, California, Montana, Kansas, New Mexico, Texas, Arizona, Wyoming.
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
Do army cutworms damage crops?
Yes, the larvae feed on small grains, alfalfa and canola, causing damage to those crops.
Source: Wikipedia
Are they a threat to gardens or shrubs?
The caterpillars can defoliate native shrubs such as sagebrush and four-wing saltbush.
Source: Wikipedia
Same family (Noctuidae)
Ipsilon Dart MothAgrotis ipsilonDamages trees, gardens or crops
Fall Armyworm MothSpodoptera frugiperdaDamages trees, gardens or crops
Large Yellow UnderwingNoctua pronubaDamages trees, gardens or crops
Silver ΥAutographa gamma
American DaggerAcronicta americanaCan irritate skin
Armyworm MothMythimna unipunctaDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Army_cutworm
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.