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Integrated Pest Management · Agriculture and Natural Resources

University of California

Scales

Greedy scale

Greedy scale (an armored scale).

Black scale

Black scale (a soft scale).

Opuntia cochineal scale.

Opuntia cochineal scale.

Yellow crawlers and the white covers of settled, first instars of San Jose scale.

Yellow crawlers and the white covers of settled, first instars of San Jose scale.

Scales do not resemble most other insects. Adult females of most species are circular to oval, wingless, and lack a separate head or other easily recognizable body parts.

Scales feed by sucking plant juices. When scales are abundant the feeding of some species can cause discoloration and distortion of leaves and shoots and plants may appear water stressed. Prolonged high populations of some species can cause dieback of terminals and reduced growth of plants.

Sticky honeydew is excreted by soft scales (family Coccidae) and certain other scales. Honeydew attracts ants, induces growth of blackish sooty mold, and fouls plants and surfaces beneath them.

Scale infestations can be annoying, innocuous, or severely damaging to plants. The importance of infestations depends on the abundance and species of scale, environmental factors, natural enemies, plant cultivar and species, and plant care practices.

Scales (overview)

  • Quick Tip: Scales (brief overview)
  • Pest Notes: Scales (common species, various types)

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Cochinillas (Scales)

Armored scales (family Diaspididae)

Soft scales (family Coccidae)

Other types of scales