Integrated Pest Management
Pine Needle Scale
Chionaspis pinifoliae
Pine needle scales (Tim Tigner, Virginia Department of Forestry, Bugwood.org)
Pine needle scales (William M. Ciesla, Forest Health Management International, Bugwood.org)
Pine needle scale damage (John A. Weidhass, Virginia Polytechnic Institute and University, Bugwood.org)
Pest Description
- females: 1/16 – 1/8 inch; white; yellowish spot at one end
- males: similar to females but smaller and narrower
- immatures: crawlers (mobile stage) 3/64 inch; yellowish orange; no wings
- immatures: nymphs (sessile stage) resemble adults, but are smaller
Host Plants, Diet & Damage
- pine (especially mugo, Austrian and Scotch); spruce; fir; Douglas-fir
- feed on sap from needles
- needles may initially be spotted yellow, turning to brown
- needle, branch and canopy dieback may occur
- heavily infested trees appear frosted
- serious infestations can cause tree death
Biology, Life Cycle & Damaging Life Stage
- overwinter as reddish eggs under the female’s cap
- crawlers present from early-May to early-June
- males and females both form scale coverings and remain stationary; males become mobile prior to mating
- second generation crawlers present late-July through August
- two generations per year
- nymphs and adults are the damaging stages
IPM Recommendations
- Keep trees healthy.
- Monitor scale crawlers from early-May to early-June and in late-July using double sided tape wrapped around twigs.
- Apply horticultural oil to smother scales or scale crawlers when monitoring indicates crawlers are present.
- Apply a systemic dinotefuran soil drench, granules or bark band in early-May.
- Imidacloprid is ineffective against hard scales.