Raspberry: Spider mites

Biology

Spider mites are tiny, eight-legged mites which may range in color from yellowish to green or red. Several species may occur on raspberries, including the twospotted spider mite. Spider mites typically feed on the underside of leaves, causing a yellowish stippling or speckling of the leaf. Severe infestations can cause entire leaves to turn yellow and drop, sometimes resulting in considerable leaf loss and reduced yield. Spider mite feeding is usually accompanied by webbing on the underside of leaves and between leaves and stems. Adults overwinter in plant debris or on canes. Mite infestations are worse in hot, dry, dusty conditions and are more common on red raspberries than on trailing berries.

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.

• Insecticidal soaps may require several applications.
• Oils and soaps must contact mites to kill them.
• Be sure to target the undersides of leaves.
• It is doubtful whether it is worthwhile to control infestations that develop after September 1.

Approved Pesticides

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

• All Seasons Horticultural and Dormant Spray Oil Concentrate [Organic]
  Active ingredient: mineral oil/pet distillate [EPA registration number: 4-80]
• Bonide Mite X RTU
  Active ingredient: clove oil, cottonseed oil, garlic oil/powder [EPA registration number: 4-04001]
• Safer Brand Insect Killing Soap Concentrate II [Organic]
  Active ingredient: potassium salts of fatty acid [EPA registration number: 42697-60]
• This list may not include all products registered for this use.

Additional Images