Scale

Description:
Scale are related to mealybugs but they have a casing that hides them so they look more like a crusty, bumpy growth on the plant. Underneath the casing they are tiny, worm-like creatures that feed on the sap of plants.

Damage:
Scale will set up shop in one area, hiding under their protective coating, and suck the life out of plants. They will attack almost any plant but are commonly found on evergreens and interior plants. Scale attach themselves to leaves, stems, and even the bark. In high numbers, they cause the foliage to yellow and may weaken the plant to the point of death.

Prevention:
Avoid introducing scale into your landscape by inspecting plants before you purchase them. Once scale is introduced it is difficult to get rid of. The hard-shell casings protect scale from the effects of contact herbicides.

Management:
Mild Infestations:
If only a few plants are affected you can remove the scale physically with a scraper of some kind or even your fingernail. Horticultural oil can control new generations by smothering them as they hatch. Several applications may be necessary. Follow label directions.

Severe Infestations: Contact insecticides are only effective when the scale are hatching and crawling around. To kill adult scale in their shells, on ornamental plants, use a systemic insecticide like Orthene or Cygon. Do not apply systemic insecticides to edible plants. Instead, use horticultural oils and dormant oils. Always apply chemicals according label directions.