Hello Cindy,

There are many species of spider mites that could be infesting your evergreens. I’m guessing that they are spruce spider mite. Learn more about spider mites, how to identify them and how to control them in the following articles.

https://entomology.ca.uky.edu/ef438

https://hgic.clemson.edu/factsheet/integrated-pest-management-i-p-m-for-spider-mites/

https://extension.umn.edu/yard-and-garden-insects/spider-mites

These articles provide management strategies that are non-chemical and chemical. An easy, non-chemical control method is with a hard spray of water on the plant, both the top and underside of the branches, which can wash the mites off and destroy their webs. It must be done frequently, before the infestation is completely resolved. There are predator insects that control mites and often, chemicals may be non-specific and kill the helpful insects in addition to the mites.

When using chemicals, read the label to ensure that it can be used on the plant in question and that it will treat the pest that you wish to control. Follow the directions on proper application of the pesticide.

Also, depending upon the species of spider mites, they could spread to other evergreen trees.

One of the best ways to protect against insect attacks is to ensure that the tree is not stressed. A tree may become stressed on hot dry summer days due to a lack of water or other environmental conditions, such as new construction near the trees.

A certified arborist will be able to assess and help you with the management of your trees. Go towww.treesaregood.org, the website of the International Society of Arboriculture to find an arborist near you.

Thank you for contacting Ask Extension.