An insect that causes needle damage on evergreens
Scales are aphid-like insects that produce a hard, waxy shell to protect themselves from predators and environmental conditions. Pine needle scale feeds mainly on the needles of pine and spruce trees. This feeding can cause needle and branch damage and with heavy Infestations can kill young trees and reduce vigor in mature trees.
Infested trees require chemical treatment for control
Colorado blue spruce, Norway, white spruce, Arborvitae, cedars, Douglas fir, hemlock, junipers, larch, and pine trees are susceptible to pine needle scale. A topical or systemic treatment is required for control. This insect rarely kills its host but with light to moderate feeding needles can turn brown and drop.
What to look for
• Thin, sparse needles.
• White spots on needles.
• White, waxy scale covering.
• Increase of infestation through the growing season.
• Needle and branch dieback.
• Red-colored eggs remain under the scale covering through the winter (overwinter).
• Eggs hatch in late May / early June.
• The new crawlers emerge over a two week period.
• After mating, the males die and females produce 100+ eggs.
• Two generations per year.
• The second generation of crawlers emerges in late July.
Treatment and Prevention
• Reduce stress in environment by reducing or enhancing watering.
• Fertilize or mulch with Applied Organic Matter.
• Needle Scale can be controlled by both soil and spray applications; depending upon the severity of infestation.
– Spray applications are required in the spring and early summer.
– A soil-applied treatment timeline is dependent upon your tree, landscape, insect infestation levels, time of season, and available treatment options.