WSU Extension


Caption: Western spotted cucumber beetle
Photo by: K. Grey
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Cucumber, Pumpkin, Squash : Western spotted cucumber beetle
(revision date: 2/14/2019)

The western spotted cucumber beetle is a pest of many ornamentals and vegetables. About 1/4" long, the adult beetles have yellow wing covers with black spots. The rest of the body is black. Adults feed on leaves of plants, while the larvae feed on the roots of some plants.
Management Options

Non-Chemical Management
  • Pick and kill individual beetles.
Select non-chemical management options as your first choice!

Chemical Management

Repeated applications are necessary most seasons. Apply when first observed on plant. Products containing esfenvalerate are toxic to bees. Do not apply any of the products listed on or near blooming plants. To minimize risk to bees, apply in the evening after bees have stopped foraging for the day.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bug Buster-O [Organic]
    Active ingredient: pyrethrins  |  EPA reg no: 1021-1771-54705
  • Monterey Bug Buster II
    Active ingredient: esfenvalerate  |  EPA reg no: 1021-1778-54705
  • 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.
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Caption: Western spotted cucumber beetle
Photo by: K. Grey
Caption: Western spotted cucumber beetle
Photo by: A.L. Antonelli