Pine needle scale, Chionaspis pinifoliae, is a conspicuous and common armored scale insect on conifers throughout the United States. Pine needle scales appear as oyster shell-shaped white blisters on the needles of conifers, often so numerous they envelop the entire needle.

Although they prefer pines they are known pests of spruce, fir, and Douglas fir causing disfiguration and often death of the infested needles and general decline of the whole tree.

Susceptible Hosts

• Pines, especially Mugho (Pinus mugo) and Scots pine (P. sylvestris) • Fir (Abies spp.) • Spruce (Picea spp.) • Douglas fir (Pseudotsuga menziesii)

Pest

Chionaspis pinifoliae

Symptoms

• Sickly, yellow appearing needles

• Heavily infested trees can appear silvery from a distance

• Thin or weak appearing canopies as infested needles are shed

Signs

• Presence of numerous, oval shaped white insects on needles

Life Cycle

• First generation eggs hatch over 2-3 weeks in mid-spring (May). Second generation eggs hatch over 2-3 weeks in mid-summer (July).

• Crawlers move to the previous year’s needles to insert their mouthparts through the stoma to feed upon which they begin to form new armor.

• 3-5 weeks later the males emerge as winged adults. Females emerge as wingless adults.

• After mating, the females grow for a couple more weeks and lay 20-60 deep reddish colored eggs under the armor. • Eggs overwinter under the armor.

• Two generations per year.

Distinguish from Look-alikes

No other scale on pine and other conifer needles in North America resembles pine needle scale

Pine needle scale is an armored scale that can have two generations per year. Insecticide applications must be timed to ensure high titer levels are within the tree when nymphs insert their mouthparts into the needles and begin to feed. Apply Transtect to the soil in the spring up to 2-3 weeks prior to crawler emergence.

Two foliar spray applications should be timed to target new crawlers from each generation. Transtect soil applications have provided good results on leaf feeding armored scales such as False Oleander Scale, Pine Needle Scale and Elongate Hemlock Scale.

Ohio State

University of Minnesota