Soft scales

Soft scale is a common pest that can be found on many different plants. They owe their name to their spherical appearance, which is their scale cover. The young stages of different soft scales are flat, light in color and often hard to find on the plant. The adult females have the cap-shaped cover which characterizes the species. The cover is fused with the body and underneath you'll find huge amounts of eggs. Eggs hatch underneath the cover and develop into first instars called crawlers. This stage is very active and will spread quickly across the plant. Second instars and older stages hardly move and stay on one place on the plant, often parallel to the veins of the leaf or on the stem.
For biological control of soft scale it is important to know which species is present in order to make a correct choice of the natural enemy to be deployed.

Soft scale occurs on many plant species. Well-known host plants are Anthurium, Asplenium, Ficus, Coffea, citrus, oleander and olive. The insects suck plant juices which may cause cosmetic damage as well as reduced growth and deformation of the leaves.
All soft scale species produce large amounts of honeydew so the affected plants become sticky ("fat"). The places with honeydew are an ideal habitat for black sooty mold. This reduces photosynthesis which is an additional detrimental effect on the plant.

 

soft scale characteristics

  • round to oval shape with a pattern of dark spots
  • young stages flat
  • adult stages flat to spherical, depending on species
  • in greenhouses and horticultural crops
  • on many different host plants
  • large amounts of  honeydew

soft scale damage

  • honeydew
  • stunted growth and malformation of leaves
  • sooty mold on honeydew

Products against soft scales:

against brown soft scale:

MICROTERYS nietnerii, parasitoid

COCCOPHAGUS scutellaris, parasitoid

ENCYRTUS lecaniorum, parasitoid

METAPHYCUS flavus, parasitoid


against hemispherical scale:

COCCOPHAGUS lycimnia, parasitoid

ENCYRTUS lecaniorus, parasitoid

METAPHYCUS flavus, parasitoid


against Hydrangea scale:

EXOCHOMUS, coccinellid


against cottony camellia scale:

EXOCHOMUS, coccinellid


against horse chestnut scale:

EXOCHOMUS, coccinellid


against black scale:

ENCYRTUS lecaniorum, parasitoid