Stress Encourages Pest Problems
Mites are opportunistic pests, usually attacking plants that are already struggling from other pest problems and/or drought or lack of light. All pest insects target weakened plants that lack vigor to resist their attack. Researchers are finding that glutathione, a chemical produced by stressed plants, enhances the reproduction, growth, pesticide resistance of pest insects. This may explain why they are attracted to already suffering plants. It also suggests that the best mite control strategy is to treat the immediate mite problem first, then determine, if possible, the underlying problem that is causing the plant stress and correct that.
Some Causes of Plant Stress
Some causes of indoor or outdoor plant stress include:
Too much or too little light or water.
Inappropriate plants for the climate or location.
Overuse of nitrogen-rich fertilizer, which encourages too much leafy plant growth.
Drastic pruning of trees or shrubs, which stimulates growth of succulent suckers.
Use of broad-spectrum pesticides which also kill the mites’ natural predators.
Transplant shock which makes plants vulnerable to mites for a few days to a week.