Bug FAQArmyworm Moth
Mythimna unipuncta · Order: Lepidoptera · Family: Noctuidae
Also called: White-speck Moth, American Wainscot, White Speck
Source: Wikipedia
Mythimna unipuncta, called the true armyworm moth or white-speck moth, belongs to the Noctuidae family and is found across much of North America and other continents. The larvae feed on many grasses and crops, and large swarms can cause serious damage to agricultural fields.
Source: Wikipedia
Is it a pest in the house?
The true armyworm is regarded as an agricultural pest. Outbreaks of large swarms occur fairly often.
Source: Wikipedia
How to get rid of it
Fields at risk should be inspected regularly, especially during the first two weeks of June. Pheromone traps help estimate adult numbers, and visible leaf damage may indicate the need for insecticides or baits.
Source: Wikipedia
What it eats
Caterpillars eat a variety of grasses and other crops, causing leaf damage. Adult moths sip nectar from flowers and may also feed on ripe or decaying fruit.
Source: Wikipedia
Life cycle
Two to three generations can develop each year, each taking about 30 to 50 days from egg to adult. During development they must avoid predators, parasitoids, and microbial diseases.
Source: Wikipedia
When you see it
They migrate north in spring and south in fall to ensure summer mating in favorable conditions. Females typically mate five or six times in their lifetime.
Source: Wikipedia
Where it comes from
Although thought to have originated in the Neotropics, it has been introduced to many other regions and is now a widespread agricultural pest.
Source: Wikipedia
Lookalikes
It is the same species referred to by several common names such as true armyworm moth and white-speck moth.
Source: Wikipedia
Where it is found in the US
Recorded in 51 of 51 states and DC. Most records: Texas, California, Illinois, Maryland, Pennsylvania, Massachusetts, Ohio, Wisconsin.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
Questions people ask
How can I monitor true armyworm populations?
Set up pheromone traps to gauge adult numbers and watch for leaf damage as a sign of larvae activity.
Source: Wikipedia
When should I check my crops for armyworm larvae?
Inspect fields regularly, focusing on the first two weeks of June for early signs of infestation.
Source: Wikipedia
What crops are most at risk from true armyworm?
The larvae feed on many grasses and other cultivated crops, so any grain or grass-based field can be affected.
Source: Wikipedia
Do true armyworms migrate?
Yes, they move northward in spring and head south again in fall to find suitable summer breeding areas.
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/Mythimna_unipuncta
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.