Physokermes spp.

 

HOST Spruce

DAMAGE/SYMPTOMS The reddish-brown covering surrounding the scale resembles a spruce bud. Because of this, they are often unrecognized. The scale releases copious amounts of honeydew that can attract black sooty mold. Heavy infestations can cause dieback of lower branches.

LIFE CYCLE The scale nymphs spend the winter on the spruce needles or bud scales. In late spring, mating occurs followed by egg laying. Egg hatch occurs in June through early July. The crawlers migrate to the needles to start feeding and then move to the twigs later in the spring. There is one generation per year.

MANAGEMENT Provide spruce trees with adequate water. Dormant oils applied in early spring followed by a contact insecticide in late June (during the crawler stage) are recommended for management. Horticultural oils and some other oils can cause discoloration of the spruce needles. A systemic insecticide with the active ingredients imidacloprid or dinotefuran can be applied in the spring.

 

A Spruce bud scale at base of twig.

 

Spruce bud scale galls at the base of spruce stems.