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Cucumber, Pumpkin, Squash: Spider mites

categories: Cucumber, Pumpkin, Squash Cucumber, Pumpkin, Squash Insects Vegetables

revision date: 2023-04-04 12:00

Spider mites under microscope.
Spider mites under microscope
Photo by: L.K. Tanigoshi

Biology

Spider mites are tiny, eight-legged mites which range in color from yellowish to green or red. They typically feed on the underside of leaves, causing a yellowish to bronze stippling or speckling of leaves. Severe infestations can cause entire leaves to turn yellow and may reduce yields. Spider mite feeding is usually accompanied by webbing on the underside of leaves. The mites may be visible as “moving dust” in the webbing. Mite infestations are worse in hot, dry, dusty conditions.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Provide proper culture. Healthy plants are more tolerant of damage, while drought-stressed plants are more susceptible.
  • Predatory mites and insects such as ladybird beetles and green lacewings aid in control of mite populations. Avoid use of broad-spectrum insecticides which kill beneficials.
  • Hose mites from plants with a strong stream of water.
  • High levels of nitrogen in the foliage encourage spider mite reproduction. Switch to a slow-release or low-nitrogen fertilizer when practical.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Several applications may be needed.
  • Begin applications when mites or their damage is first observed (usually late spring).

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

  • Bonide Mite X RTU
    Active ingredient: clove oil, cottonseed oil, garlic oil/powder [EPA registration number: 4-04001]
  • RID-BUGS
    Active ingredient: rosemary oil, clove oil, sesame oil [EPA registration number: 998920-08001]
  • Safer Brand BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic]
    Active ingredient: azadirachtin [EPA registration number: 70051-6-42697]
  • Whitney Farms Insecticidal Soap [Organic]
    Active ingredient: potassium salts of fatty acid [EPA registration number: 67702-21-73327]
  • This list may not include all products registered for this use.

Additional Images