armyworm

noun

ar·​my·​worm ˈär-mē-ˌwərm 

: any of numerous moths whose larvae travel in multitudes from field to field destroying grass, grain, and other crops

especially : the common armyworm (Mythimna unipuncta) of the eastern and central U.S. and Canada

Examples of armyworm in a Sentence

Recent Examples on the Web

As global temperatures rise, pests like the fall armyworm, widely known for damaging crops like corn, are advancing northward, causing severe damage in areas from Texas to the Midwest, where these threats were previously unheard of. —Valeria Kogan, Forbes, 24 Feb. 2025

Meanwhile, researchers want to expand the use of RNA pesticides to lepidopterans, which include major moth pests such as corn borers and the fall armyworm. —Byerik Stokstad, science.org, 27 June 2024

The company is currently testing its effectiveness on the fall armyworm and two other pests. —Byerik Stokstad, science.org, 27 June 2024

No one wants to lose their watermelons to pests like aphids, armyworms, or cucumber beetles, so keep your eyes peeled for these pesky insects. —Lauren Landers, Better Homes & Gardens, 8 July 2024

Word History

First Known Use

1815, in the meaning defined above

Phrases Containing armyworm

• beet armyworm
• fall armyworm

Kids Definition

armyworm

noun

ar·​my·​worm -ˌwərm 

: any of numerous moths that in the larval stage travel in large numbers from field to field destroying crops (as grass or grain)