Spruce and fir trees can provide a wonderful backdrop to your property. Their foliage offers an evergreen display all year round and their fallen cones can be used for decorative purposes or for fire kindling once the local wildlife has harvested the nutritious seeds inside.

Unfortunately, a great many varieties of spruce and fir trees can be vulnerable to attack by the spider mite pest. So, how do you spot spider mites and what action can you take to get rid of them?

Identification of spider mites

Spider mites are active during the cooler months of the year. They are particularly keen on the following species of trees:

• fir
• spruce
• hemlock
• juniper
• arborvitae

Spider mites can be seen at the base of the tree's needles where they feed on the sap. To the naked eye the mites look like greenish-yellow or orange-red dust and are often mistaken for harmless pollen. A sure sign that the infestation is accelerating are patches of white silk webbing, which contains cast mite skins, indicating a previous moult.

Intense feeding strips so much sap from the tree's needles that they turn yellow or brown and begin to drop, leaving the tree with sparse areas on its branches. If the infestation is not dealt with and is allowed to thrive, the tree may begin to lose branches and will eventually die. Once the tree is no longer producing sap to feed the mites, they will readily spread to neighbouring specimens.

Treatment of spider mites

If you spot a spider mite infestation quickly, you can kill them and halt their spread to other trees on your land.

You can obtain a suitable miticide treatment or dormant oil from your local garden centre or DIY store. However, applying the treatment can be tricky if the trees are tall or very large. In such cases, the best course of action is to ask your local tree services company to attend and treat your trees.

Any trees that are very badly damaged and infected by the mites may need to be removed. In such cases, the wood and branches should be burned to ensure that all the mites are killed and any eggs are destroyed to prevent the infestation spreading to other trees.

In conclusion

If one of your trees shows signs of spider mite infestation, don't delay. Give your local tree services company a call and ask them to deal with the problem for you.