Scale is a soft-bodied insect that hides beneath a shell-like covering. As the insect feeds on plant juices, it excretes a waxy or wooly substance that forms this protective coating. Scale usually appears as smooth and brown or thick and white bumps on plant stems or leaf surfaces. When a plant is under attack from scale, its leaves gradually yellow and it loses vigor. Severely infested plants may die.

Females lay eggs beneath the protective shells. Newly hatched scale insects have legs and are able to move about and establish themselves in new areas. Eventually, female “crawlers” settle into place and become immobile. Male crawlers transform into a winged form. Scale is found throughout North America.

Prevention and Control
  • Use your fingernails to scrape scale off of twigs.
  • Prune off and destroy scale-infested twigs and branches.
  • Encourage beneficial including lady beetles, soldier beetles, and parasitic wasps.
  • Remove scale from leaves by dabbing with a cotton swab moistened with rubbing alcohol or a soft cloth soaked with soapy water. Rinse plants well after this treatment.

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