Answer: That sounds like it could be spider mites. Check the undersides of the affected leaves for a "dirty" or "rusty" appearance. The mites are very tiny, usually reddish colored and they leave small webs. Spider mites are best controlled with a daily blast of water from the hose. (Mites like dusty plants.) Spray underneath leaves, between stems, etc. The humidity from the extra water also helps the plant. If that doesn't work, try an insecticidal soap. You will probably need to monitor the situation for some time before getting them all under control. If plants are heavily infested, you may need to discard them and start afresh.
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