University of Illinois Extension

University of Illinois Extension

Hort Answers

Insect Damage

Spruce Bud Scale
Physokermes piceae

Spruce bud scale
Spruce bud scale
2 (1 = rare 5 = annual)
4 (1 = very little damage 5 = plants killed)
Spruce bud scale mainly attacksNorway spruce, but it will attack other spruces.

Plants Affected
This scale is small and is often clustered in-groups of 3 to 8 at the base of new shoots. Their size and color often allows them to be overlooked or mistaken as buds. They are round and reddish-brown in color. Lower branches are more often attacked than higher branches. Severe infestations can produce sufficient honeydew to allow sooty mold to grow. In addition severe infestations can cause lower branches to die, especially on trees that are already weak or stressed.

Life Cycle
There is only one generation per growing season. The immatures overwinter on the under side of the needles. In the spring, the females move onto the twigs to complete their development. Crawlers usually appear in June.

If needed, apply a suggested insecticide. Apply when Hills-of-Snow hydrangea is in bloom. Summer oils will turn blue spruces green.

Related Resources
Home, Yard & Garden Pest Guide
Illinois Commercial Landscape and Turfgrass Pest Management Handbook
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic