Asparagus: Cutworms and armyworms

• Categories: Asparagus Asparagus Insects Vegetables
• Last review date: 2026-02-12 09:04

Biology

Cutworms and armyworms are the larvae of noctuid moths. These common moths are medium sized with fairly dull coloration. The gray to tan caterpillar are hairless, nocturnal, and generally spotted, striped, or otherwise marked. They may be 1/4″ to 1″ in length and tend to curl up when disturbed.

Cutworms may climb up and feed on the growing spears of asparagus. They also eat through stems of asparagus and many other plants, cutting them off at ground level.

While armyworms typically feed during the day, cutworms spend the day just beneath the soil surface or under debris near the host. They usually feed at night, so it is advisable to search for them with a flashlight in the dark. Weeds are their primary food source.

Management Options

See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.

Non-chemical Management

Select non-chemical management options as your first choice!

• Control weeds and grasses in and near the garden.
• Remove debris around plants that provides shelter for cutworms.
• Hand-pick night-feeding larvae, when practical. Scratch soil at the base of damaged plants to find larvae in the daytime.
• Encourage natural enemies of cutworms including birds and spiders.

Chemical Management

• Apply when damage first appears.

Approved Pesticides

If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.

• Bonide Pyrethrin Garden Insect Spray Concentrate
  Active ingredient: pyrethrins, piperonyl butoxide
  EPA registration number: 4-371
• Bug Buster-O [Organic]
  Active ingredient: pyrethrins
  EPA registration number: 1021-1771-54705
• Safer Brand BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic]
  Active ingredient: azadirachtin
  EPA registration number: 70051-6-42697
• This list may not include all products registered for this use.