WSU Extension

Hortsense

Lawn and Turf : Cutworms
(revision date: 3/10/2017)


Biology
Cutworms are the larvae of noctuid moths. These common moths are medium-sized with fairly dull coloration. The greenish, grayish, or tan caterpillars 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 feed by chewing leaf blades or cutting through stems near the soil line. Cutworms typically spend the day just beneath the soil surface or in the thatch. Weeds are the primary food source for cutworms, which may spread into lawns when numbers are high. They cause little real damage to lawn grasses. Cutworm infestations may be common in older lawns, particularly those with a lot of bentgrass.
Management Options

Non-Chemical Management
  • Control weeds in and near lawn areas.
  • Encourage natural enemies of cutworms including birds and spiders.
  • Hand-pick and kill cutworms when noticed.
Select non-chemical management options as your first choice!

Chemical Management

One of the following products may be used if this problem is identified. Most lawn insecticides are highly toxic to bees. Mow or remove weed flowers before applying.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bull's-Eye Bioinsecticide
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 62719-314-56872
  • Monterey Garden Insect Spray [Organic]
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 62719-314-54705
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • This list may not include all products registered for this use.
Images
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Caption: Redbacked cutworm
Photo by: K. Grey
Caption: Spotted cutworm
Photo by: K. Grey
Caption: Cutworm eggs
Photo by: A.L. Antonelli