How to Control Spider Tree Mites

Extreme close up of a spider mite

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Spider tree mites are eight-legged arachnids that belong to the same class as spiders and are closely related to ticks. Like spiders, they will produce webbing on the plant. Spider mites come in a wide variety of colors, including red, yellow, green, and brown. Some even change colors throughout the year, while others are translucent.

Spider tree mites are among the most commonly found pests in gardens. Hundreds of different species are categorized as spider mites, which are members of the Tetranychidae family. These critters can damage plants by sucking on the tissues, mainly in the leaves. The mites often cluster on the undersides of leaves.

Signs of an Infestation

Spider tree mites leave visible signs of damage to trees. If your leaves develop yellow, orange, brown, or gray spots, an infestation may be at work. Other signs of infestation include:

  • Leaf drop
  • Webbing covering the plant
  • Visual confirmation of the presence of mites
Parlatoria on leaves and branches of Euonymus japonica. Mealybugs, plant disease white insect small.
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Common Tree and Shrub Hosts

While any tree or shrub may fall prey to spider mites, some are more common as hosts. These include:

Biological Controls

To control them, try biological methods. Several insects and arachnids are natural predators of spider mites. Encourage these helpers by limiting the use of chemicals in the garden. Natural predators of spider tree mites include:

  • Big-eyed bugs (Geocoris spp.)
  • Gall midge (Feltiella acari Suga)
  • Lacewings (Chrysopa spp.)
  • Minute pirate bugs (Orius app)
  • Predatory mites (Phytoseiidae Family)
  • Predatory thrips (Scolothrips spp.)
  • Spider mite destroyer (Stethorus app., a genus of lady beetle)

Organic Controls

Two popular organic methods for controlling spider mites include horticultural oils and insecticidal soaps. For example, oil from the neem tree (Azadirachta indica) can be used as an organic miticide. The timing of when you apply these oils depends on the product used, so consult with an expert at your local garden center, nursery, or extension office to determine the best application time for your situation.

For an inexpensive and safe formula to attack spider mites, combine 2 tablespoons of natural soap with 1 quart of water. Do not add extra soap, as too much may cause leaf damage. For an added punch, include garlic or cayenne.

Worker watering plants in plant nursery greenhouse
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Water as a Control

Spider mites attack plants that are suffering from drought, so proper watering is essential to help ward off these invaders. Water is also useful in controlling spider mite infestations on houseplants, where it is harder to bring in natural predators and the use of chemicals is undesirable. Soak or spray plants with a faucet or hose to knock off mites and webbing, making sure to hit both sides of the leaves. You can set indoor plants in a bathtub to help make this process less messy.

Chemical Controls

Using chemicals should be a last resort. Acaricides may be able to control the spider mite infestation, but they do not discriminate and will attack the beneficial predators also, especially the predatory mites. This will reduce the possibility of natural control for a number of pests in your garden.