WSU Extension


Tomato : Colorado potato beetle
(revision date: 3/22/2021)

The adult Colorado potato beetle is a broad (1/4" wide), yellow-and-black striped beetle up to about 3/8" in length. The adults overwinter in the soil, emerging in the spring. They lay clusters of yellow eggs on the underside of the leaves of host plants. The humpbacked larvae are reddish-orange and have two rows of black spots along each side. Both larvae and adults chew holes in leaves and leaf margins. They may cause serious defoliation. Other plants which may be attacked include pepper, potato, petunia, and other tomato relatives including weeds such as nightshade and groundcherry.
Management Options

Non-Chemical Management
  • Eliminate weeds in and around the garden, especially nightshade and related species.
  • Hand-pick and kill adults and larvae.
  • Crop rotation to non-host plants may be useful if host species are not planted nearby.
Select non-chemical management options as your first choice!

Chemical Management

Follow label instructions. Apply when beetles or damage begins to appear. Beneficial nematodes can be ordered through certain nurseries. They may control the larval stage if applied when soil temperatures are warmer than 52 F. Nematodes should not be applied in direct sunlight and the soil should be saturated with water prior to application.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bonide Captain Jack's Deadbug Brew R-T-U [Organic]
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 4-472
  • Bug Buster-O [Organic]
    Active ingredient: pyrethrins  |  EPA reg no: 1021-1771-54705
  • Monterey Garden Insect Spray [Organic]
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 62719-314-54705
  • Natural Guard Spinosad Bagworm, Tent Caterpillar & Chewing Insect Control
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 62719-314-7401
  • 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.
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Caption: Colorado potato beetle adult
Photo by: Clemson University
Caption: Colorado potato beetle adult
Photo by: Unknown
Caption: Colorado potato beetle larva
Photo by: Unknown