It may not look like an insect, but the pine needle scale is one species in a group of tiny insects called armoured scales. Beneath the scale-like shell the tiny insect sucks the sap from needles. Oddly, pine needle scale is more common in Calgary on spruce than pines. Once on a suitable needle, the scale secretes a protective white shell over its body and remains in place for the rest of its life. Scales begin life as over wintering eggs beneath the shell of their now dead mother. In mid-June they hatch and emerge as very tiny red crawlers and move a short distance to settle, secrete a shell and begin feeding. The red crawlers are easily blown by the wind to neighbouring trees.
Needles become pale looking and whitish as scale feeding progresses. Needles eventually become deformed and stunted and then die from the feeding. Excessive infestations can seriously deform or kill a tree. Young trees, rather than mature trees are more likely to be attacked.
- Chemical sprays are effective only in the very brief stage in mid-June that the red crawler has emerged. Once the telltale white shell has been secreted, sprays will no longer work.
- Badly infested trees should be removed.