jump directly to content.
Principles. Crops. Pests. Control methods Library. Links.
key visual: online information service for Non-chemical Pest Management in the Tropics

General Information

Common names: Scales
Order: Homoptera
Synonym: Coccoids

Host plants

Citrus and other fruit trees, banana, cacti, orchids and other tropical ornamentals, palms, figs, grapes, shrubs




Scales remove plant saps by using their sucking mouthparts. Leaves become stunted and turn yellow. Twigs and branches dieback and eventually the plant dies when the population level is high. Some scale species produce honeydews which they secrete while feeding. Honeydews on fruits, leaves, twigs, branches, and barks attract black sooty molds to feed and grow, causing these plant parts to blacken (Olkowski; Daar; Olkowski, 1991: p. 375-378).


  1. Armored scales (Diaspididae)
    Armored scales are small, about 3 mm long. Their colors vary from white, yellow, gray, reddish or purplish. Adults are oval or round, hard bumps, and sometimes bearing a nipple or dimple in the center. They do not produce honeydews but they secrete armor wax in an oyster shell or circular pattern. They remain attached to the host plant when shells are lifted up (Olkowski; Daar; Olkowski, 1991: p. 375-378).
  2. Soft Scales (Coccoidae)
    The eggs are covered or found under the mother scales. Eggs hatch into crawlers (nymphs), which are flattened and looking like dusts on the plant surface. Adult females are either oval or round, soft, legless bumps, and are wingless. Males are tiny yellow-winged soft scales. Soft scales secrete honeydews which attract ants. The shells of the soft scales are not left on the plant when lifted up. The soft covering they secrete cannot be separated from the scale's body. Soft scales typically move between branches and leaves during their lifecycle (Olkowski; Daar; Olkowski, 1991: p. 375-378).
 to the top        PAN Germany, OISAT; Email oisat@pan-germany.org