Needles are stippled, yellow, and dirty. A silken webbing may be on the twigs and needles. Needles usually turn brown and fall off. To check for mites, hold a sheet of white paper underneath some stippled needles and tap the foliage sharply. Minute dark green to black specks can be easily seen as they begin to crawl around.
Apply an insecticide labeled for this pest, following label directions.