Pine and Spruce Insects

Spruce Mite

Spruce Spider mite (Oligonychus ununguis) is not an insect. It has eight legs and is thus considered an "insect relative". It feeds on pine, spruce and many other needled evergreens. Thin silk strands may be found due to mite infestation. Stippling – the tiny yellow to whitish spots due to feeding, may cause the needles to die and turn reddish brown when infestations are severe. Spruce mites, feeding in the spring when temperatures are cool, tend to return in the fall in higher numbers. At first young mites (larvae) have six legs but after one molt they have eight legs. The adult mites tend to be green but can be brown. Spruce mites use the wind and their silk strands to disperse.

Reduce stress on trees. Use a sheet of white paper to check for mites starting when saucer magnolia is in pink bud to early bloom. Shake or rap the spruce branch on the paper. If tiny green to brown slow moving "dust particles" are seen a miticide may need to be applied Spruce mites leave a green streak or blotch when crushed. DO NOT use an insecticide. Insecticides tend to increase a mite problem by killing off the predatory mites. Check with your local land grant university (Cooperative) Extension Service for recommended miticide.

Written by James Schuster, Extension Educator, Horticulture, and reviewed by Dr. Phil Nixon Extension State Specialist, Entomology, University of Illinois at Urbana-Champaign.