ar·​my·​worm | \ ˈär-mē-ˌwərm How to pronounce armyworm (audio) \

Definition of armyworm

: any of numerous moths whose larvae travel in multitudes from field to field destroying grass, grain, and other crops especially : the common armyworm (Pseudaletia unipuncta) of the eastern and central U.S. and Canada

Examples of armyworm in a Sentence

Recent Examples on the Web And the threat of swine fever and armyworm in China would diminish if the country wasn’t so dedicated to using the appetites of its people as a trade-war bargaining chip. Washington Post, "Diseases Are Killing Our Food, But Don’t Panic," 11 June 2019 The drought has also given rise to armyworms and other pests that can damage crops. Washington Post, "‘Flash drought’ brings dust and dread to Southern farmers," 10 Oct. 2019 Some of those successes include fighting armyworms. Gwynn Guilford, Quartz, "Ravenous armyworms are eating their way across China," 20 June 2019 Warmer temperatures could accelerate armyworm reproduction. Gwynn Guilford, Quartz, "Ravenous armyworms are eating their way across China," 20 June 2019 Somehow the wrong picture was set with the armyworm story. Tom Maccubbin,, "Leaving seed pods on canna plants isn’t necessary," 7 June 2019 Pests monitored: Pheromone lures are available for diamondback moths and moths that produce armyworms, cabbage loopers, corn earworms, European corn borers, tomato pinworms, and cutworms. The Editors Of Organic Life, Good Housekeeping, "The 7 Best Organic Pest Control Techniques For Your Garden," 18 Dec. 2017 Answer: Gardeners in all Florida counties have problems with armyworms and similar corn feeders. Tom Maccubbin,, "Keep corn feeders in check with natural sprays," 21 Apr. 2018 Syngenta invested over $100 million and 15 years in developing Viptera, which has a trait called MIR162 that protects against pests such as earworms, cutworms, armyworms and corn borers. Washington Post, "1st farmer lawsuit on deck against Syngenta over China trade," 5 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'armyworm.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of armyworm

1815, in the meaning defined above

Keep scrolling for more

Learn More about armyworm

Time Traveler for armyworm

Time Traveler

The first known use of armyworm was in 1815

See more words from the same year

Statistics for armyworm

Cite this Entry

“Armyworm.” Dictionary, Merriam-Webster, Accessed 22 Jan. 2021.

More from Merriam-Webster on armyworm Encyclopedia article about armyworm

Comments on armyworm

What made you want to look up armyworm? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Slippery Words Quiz—Changing with the Times

  • ducreux self portrait yawning
  • What is an earlier meaning of nice?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!