army cutworm

{{short description|Species of moth}}

{{Speciesbox

| name = Army cutworm

| image = Euxoa_auxiliaris.jpg

| taxon = Euxoa auxiliaris

| authority = (Grote, 1873)

}}

The army cutworm is the immature form of Euxoa auxiliaris.{{ITIS |id = 117386 |taxon = Euxoa auxiliaris | accessdate = July 9, 2007}} Together with other moths that are locally abundant and that have scales that dislodge from the wings, the adult moth is called a miller moth.{{cite web |url=https://urbanipm.montana.edu/documents/entomology/fact_sheets/insect_fact_sheet_millermoths.pdf |title=Miller Moths |author=Laurie Kerzicnik |date=28 June 2022 |publisher=Montana State University Extension Service |access-date=24 January 2025}}

Image:Euxoa auxiliaris caterpillar.jpg

These native North American larvae consume emerging small grains, alfalfa, and canola in the southern Great Plains{{cite report |last1=Michaud |last2=Bauernfeind |first1=J.P. |first2=R.J. |title=Army Cutworm |publisher=Kansas State University, Manhattan, KS |date=2014 |id=Fact sheet MF3150 |url=http://www.bookstore.ksre.ksu.edu/pubs/MF3150.pdf |access-date=2 January 2018 }} and southern Canada.{{cite web |last1=Meers |first1=S. |title=Army cutworm |url=https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2475?opendocument |website=Alberta Agriculture & Forestry |publisher=Alberta Agriculture |accessdate=2 October 2018 |archive-date=3 October 2018 |archive-url=https://web.archive.org/web/20181003061932/https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2475?opendocument |url-status=live }} Larvae{{clarify|where are the eggs laid? when? (overwinter?)|date=June 2020}} feed above ground at night and usually hide in soil during daylight, but will also feed on cloudy days.{{cite report |last1=Peairs |first1=F. |title=Caterpillars in small grains |publisher=Colorado State University Extension, Fort Collins, CO |date=2010 |id=Online fact sheet 5.577 |url=http://extension.colostate.edu/topic-areas/insects/caterpillars-in-small-grains-5-577/ |accessdate=28 January 2018 |archive-date=11 February 2018 |archive-url=https://web.archive.org/web/20180211033239/http://extension.colostate.edu/topic-areas/insects/caterpillars-in-small-grains-5-577/ |url-status=live }}{{clarify|what is the life cycle? how long stay larvae? how do they pupate? how long do they pupate before emerging as adults? ... and, presumably, begin their migration to higher/cooler elevations|date=June 2020}}

On dry, low elevation rangelands of the U.S. Intermountain West, army cutworms consume exotic cheatgrass (Bromus tectorum) and mustards to produce cheatgrass "die-offs." Within these bare areas, the larvae also defoliate native shrubs including four-wing saltbush (Atriplex canescens) and sagebrush (Artemisia spp.).{{cite journal |last1=Salo |first1=C. |title=Army Cutworm Outbreak Produced Cheatgrass Die-offs and Defoliated Shrubs in Southwest Idaho in 2014 |journal=Rangelands |date=15 August 2018 |volume=40 |issue=4 |pages=99–105 |doi=10.1016/j.rala.2018.05.003 |s2cid=91086117 }}

The miller moth is a seasonal nuisance in the spring in states including Montana, Texas, Oklahoma, Colorado, Wyoming, New Mexico, and Kansas, as they hatch in the low-lying farmlands, then migrate to higher elevations for the summer. They return as the weather cools but in smaller numbers. They are considered nearly impossible to control through normal pest extermination techniques because a new batch shows up every day as they migrate. With their very small bodies, they enter homes (attracted by the light) in the evening through any available crack or crevice (doorjamb, chimney, etc.) and residents in migration paths report dozens of moths per day entering their homes and garages. However, other than being a nuisance, they are not considered harmful.{{cite web|url=http://hutchnews.com/Todaystop/BC-KS--Miller-Migration-1st-Ld-Writethru-20120424-16-38-37 |archive-url=https://archive.today/20120717220821/http://hutchnews.com/Todaystop/BC-KS--Miller-Migration-1st-Ld-Writethru-20120424-16-38-37 |url-status=dead |archive-date=2012-07-17 |title=The Hutchinson News Online Edition |publisher=Hutchnews.com |accessdate=2013-05-26 }}{{cite web |url=http://www.gazette.com/news/early-137375-year-crevasse.html |title=Run! Hide! The miller moth invasion has begun |publisher=Gazette.com |date=2012-04-23 |accessdate=2013-05-26 |archive-url=https://web.archive.org/web/20120622205516/http://www.gazette.com/news/early-137375-year-crevasse.html |archive-date=2012-06-22 |url-status=dead }}{{cite web |url=http://lexch.com/news/regional/article_cd619afe-8eed-11e1-90d9-0019bb2963f4.html |title=Warm temperatures bring in miller moths - Lexington Clipper-Herald : News |publisher=Lexch.com |date=2012-04-25 |accessdate=2013-05-26 |archive-date=2021-03-01 |archive-url=https://web.archive.org/web/20210301042828/https://lexch.com/news/regional/article_cd619afe-8eed-11e1-90d9-0019bb2963f4.html |url-status=live }}