WSU Extension

Hortsense

Asparagus
 
Disease
Rust 
Insect
Asparagus aphid 
Asparagus beetle 
Cutworms and armyworms 



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Caption: Bertha armyworm
Photo by: K. Grey
  
Asparagus : Cutworms and armyworms
(revision date: 5/11/2015)


Biology
Cutworms and armyworms are the larvae of noctuid moths. These common moths are medium-sized with fairly dull coloration. The gray to 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 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


Non-Chemical Management
  • 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.
Select non-chemical management options as your first choice!

Chemical Management

Apply when damage first appears.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bonide Pyrethrin Garden Insect Spray Conc.
    Active ingredient: pyrethrins  |  EPA reg no: 4-371
  • Bug Buster-O [Organic]
    Active ingredient: pyrethrins  |  EPA reg no: 1021-1771-54705
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • 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: Bertha armyworm
Photo by: K. Grey
Caption: Spotted cutworm
Photo by: K. Grey
Caption: Cutworm eggs
Photo by: A.L. Antonelli
Caption: Western yellow stripe armyworm adult
Photo by: A.L. Antonelli