Spruce Spider Mite
Attacks:
Colorado, Norway, white pine, arborvitae, cedars, Douglas fir, hemlock, junipers, larch, and pine.
What you will see:
- Stippling of needles (small yellow or tan dots)
- Single strands of webbing
- Shake a branch over a white piece of paper
- Spider mites are slow moving and green when squished
- Fast moving red dots are predatory mites
Life cycle:
- Mites overwinter as eggs on bark and needles
- Eggs hatch in April and May
- Mites are most active during the cool seasons
- April and May
- September and October
Cultural practices:
- Use low nitrogen fertilizer
- Make sure watering is adequate
- Trees planted too close together are more susceptible
- Shaded trees are more susceptible
- Place flowering plants in vicinity - they will provide increased nectar sources for predators
Chemical practices:
- Spider mites are susceptible to topical insecticides. Check with your Arborist for recommended treatment.