When you begin to observe the leaves on your trees dying, turning brown, bronzing and sometimes with webbing present it is very possible that you have spider mites.
If you want to know whether mites are present you may try the following test. Place a clean sheet of white paper on a flat surface. Take a few of the leaves that look like they are damaged. Hold them about 3 to 6 inches above the white sheet of paper and flick the leaves in the direction so that anything that may be on them will fall onto the paper. After several flicks you should see small flecks on the paper. Use a pen to make small circles around several of the small specks on your paper. The penned circles help with seeing movement. If the specks begin to move then mites are definitely present.
Spider mites tend to become more active as temperatures increase. Stressed trees and shrubs that are suffering from water and nutrient deficiencies become more vulnerable to accelerated damage because of their inability to fend off mite damage by plant health and vigor alone.
Some control options include horticultural oils, insecticidal soaps, insecticides/miticides/acaricides and predaceous mites.
Extermiman® has the equipment needed for trees that are larger than those that a person can reach with hand held equipment, back pack sprayers and small ladders or situations where many trees and shrubs are present.