- Spruce Spider mite
- Feed on needled evergreens and most active during the spring. Damage appears as stippling as mites feed on chlorophyll. Heavily attacked foliage will turn brown.
- Hosts are Juniper, pine, douglas fir, fraiser fir, and larch.
- Spend the summer as eggs, hatch again in the fall.
- Vigorously shake the tree to scout on top of white paper. Smash dots. Those making greenish streaks are usually spider mites that are feeding on the foliage; those making yellow-orange streaks are usually predaceous mites that are feeding on the spider mites.
- Insecticidal soap, miticides, and spray again in another week.
- Hard water spray foliage.
- Look for predators
- Zimmerman Pine Moth
- Pitch flows from wounds of trees.
- Kills branches.
- Host all pines but primarily Scots and Austrian pine.
- Adults active in mid-July to mid-August laying eggs.
- Eggs hatch in August.
- Larvae feed on bark and buds.
- Overwinter in hibernaculum (silken web).
- Emerge in April and bore into stems.
- Prune out damaged branches.
- Drench bark with permethrin in spring and then again in mid-August for younger larvae.
- Plant resistant varieties.
- Eastern Tent Caterpillar
- Heavily infested trees defoliate but soon leaf out again.
- Stresses tree.
- Larvae hatch at bud break of their hosts.
- When newly hatched the larvae are black but develop yellowish whitish stripes.
- Larvae migrate to crotch angle of a tree where they form a communal tent.
- They leave the tent throughout the day and feed on leaves as they grow bigger so does the tent.
- When they are fully grown caterpillars they find a protected source and pupate.
- Adult moths emerge two weeks later brown with white bands.
- After mating, female moths lay their eggs in reddish brown clusters that wrap around pencil-size-diameter branches. Each egg mass is about 1/2 inch long and contains 100 to 300 eggs. These eggs do not hatch until the following spring when bud break occurs.
- Removal tents at night.
- Spray Bacillus thuringiensis kurstaki, Spinosad, Neem Oil or Permethrin.
- Apply as young larvae have hatched when saucer magnolia is in pink bud.
– Phil Nixon. University of Illinois Extension Specialist in Entomology.
– Pest Management for the Home Landscape. University of Illinois Extension
– Coincide: The Orton System of Pest Management. Donald A. Orton and Thomas L. Green Ph.D.
– Insects that Feed on Trees and Shrubs. Warren T. Johnson and Howard H. Lyon
– Morton Arboretum Plant Health Care Reports
– Home, Yard and Garden Pest Newsletter. University of Illinois Extension
Photos by Phil Nixon and Rhonda Feree