Spruce spider mite

You will see tiny yellow speckles and grayish spots on spruce needles, particularly on older foliage in the lower crown. Damage develops in spring and again in fall when temperatures cool. Needles may turn reddish-brown and eventually drop. Fine webbing traps debris between needles, making the tree appear dusty or discolored. Heavy infestations stunt branch growth and cause premature needle shedding.

Spider mites overwinter as eggs on needle surfaces; moderate winters support multiple generations yearly. Spray horticultural oil in late fall before bud break or use miticide at first sign of spring yellowing. Encourage natural predatory mites by avoiding broad-spectrum pesticides. Frequent irrigation reduces mite pressure.