Oystershell Scale is the the most common and damaging scale insect in Colorado that develops on the bark, trunk, and limbs of a variety of trees and shrubs such as, Aspen, Ash, Cotoneaster, Poplars, Willows, and Lilacs.
Oystershell Scale weakens and damages plants by feeding on the fluids of cells underneath bark on limbs and trunks. This contributes to limb dieback and eventual plant death.
Early spring Dormant Oil Sprays are most effective in smothering overwintering insects and controlling the spread of Scale.
Mid-Summer sprays can also be utilitzed in severe cases.
Pine Needle Scale feeds on the needles and bark of pine needled trees and shrubs. There are 2 main types of Scale that affect conifers: Pine NeedledScale and Striped Scale. Both types damage needles and lead to needle drop and branch dieback, affecting the overall health of the tree.
Pine Needled Scale looks like white flecks of paint on the needles. Striped Scale appears as brown or orange nodules at the base of the needles. Striped Scale can secrete a honeydew (waste excrement) that attracts bees, wasps, ants, and flies, and also provides a breeding ground for the growth of Sooty Mold, which further discolors and deters from the look of the tree.
Both types of Pine Needle Scale can be treated in Early Spring with a Dormant Oil Spray or in cases of severe infestation can be treated with a mid-summer spray.