Damage (Mussel scale)

Mussel scale on apple
  • The main damage is caused by the presence of mussel scales on the surface of fruits at harvest.
  • The contamination is superficial but may downgrade the fruit.
  • Very heavy infestations on the bark may debilitate the tree and there may be some contamination of the foliage with honeydew.
  • At first, the upper surface of the leaves assumes a glistening, sticky appearance but it later becomes unsightly with the growth of sooty mould fungi on the honeydew.