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

Preventive Control

Natural enemies


  1. Parasitic wasps
    Aphytis melinus is a tiny yellow parasitic wasp that parasitizes armored scales while Metaphycus helvolus is a tiny black and yellow wasp that parasitizes soft scales (Ellis; Bradley, 1996: pp. 320-321). They both lay their eggs inside the bodies of living scales. The eggs hatch and the larvae of the parasitoids eat the bodies of the scales from the inside. The emerging wasps cut holes in the scales, fly off to feed and mate, then look for new live scales to lay their eggs (Olkowski; Daar; Olkowski, 1991: p. 376).
  2. Tachinid fly

  1. Hoverfly
  2. Lacewing
  3. Ladybird beetle
  4. Mealybug destroyer
  5. Minute pirate bug


Check plants for scale infestations regularly. To monitor, use your thumbnail to flip-over suspicious looking bumps on twigs and branches. When a soft-body is beneath a cover, the plant is likely to have armored scales. When a bump can be squashed and honeydews are present, soft scales are likely to be present (Olkowski; Daar; Olkowski, 1991: pp. 375-378).

Management and cultural practices

  1. Grow healthy plants through proper watering, fertilization, and weeding. Scales lives on plants that are under stress (Sadof, 2002).
  2. Provide just enough nitrogenous fertilizer to keep the plants healthy. Split nitrogen application. Scale population increases when plants are soft and juicy.
  3. Prune and dispose of infested twigs, branches, and fruits (Sadof, 2002).
 to the top        PAN Germany, OISAT; Email oisat@pan-germany.org