Red Spider Mite
How to get rid of red spider mite in large oak tree that is killing it. It is a 30 year old tree, 2 1/2 ft in diameter at the base. It is on one side of tree, at the top, and killing branches on that side. It is the side that is in the sun.
Nearly all insecticides have little effect on Spidermites. You have to buy a true Mitacide to get to them, check at your local garden center or nursery and see what they have available. Be sure to tell them it is to get rid or Mites. There are some systemics on the market that are very good at getting rid of pests. You put it around the base of the tree out by the drip line, working it into the soil well. Then water well. As it goes up through the root system and into the tree, it will kill what is feeding on the tree or causing problems. Spraying the tree and using a systemic may be in order if it is under heavy attack since the systemics can take a while to work.