cottony camellia scale on yew

Cottony camellia scale on yew. Photo: Dawn Dailey O'Brien, Cornell University, Bugwood.org

Updated: June 22, 2021

Key points

  • Cottony camellia scale (Pulvinaria floccifera) is a soft scale insect that feeds on camellia, holly, yew, euonymus, sweetbox, and maple. It also has been reported on beautyberry, jasmine, mulberry, and hydrangea.
  • It is also known as cottony taxus scale. 
  • The scale tends to be found on the underside of leaves.

Life Cycles and Descriptions

  • Adult females are about 1/8 inch long, oval and yellowish tan with a brown margin.
  • They lay white cottony ovisacs (egg masses) on the undersides of leaves in May.
  • Crawlers hatch through June and remain on the undersides of the leaves through winter.
  • There is one generation of this scale per year.

Damage

  • Heavy infestations in the spring may cause the leaves to turn light green.
  • Honeydew (a sticky substance produced by the scale insects as they feed) and sooty mold (a black fungus that grows on top of the honeydew) are the primary problems caused by this insect.
sooty mold on sweet box
Sooty mold on sweetbox (Sarcococca spp.)

Management

  • Natural predators such as lady beetles (Hyperaspis sp.) specialize on feeding within the egg sacs of Pulvinaria scales and provide natural control of this scale.
  • If infestations are heavy and sooty mold is objectionable, use a summer rate of horticultural oil (refer to the product label) in June, when beneficial lady beetles go into aestivation (summer dormancy) and the scale crawlers (juveniles) are active and most vulnerable to the spray.
  • There is one generation of this scale per year.