This scale insect or Coccid (tig. 345) resembles a miniature mussel shell in form, about § to 1/8 in. long in the female and brown in colour, closely applied to the bark of the stem and twigs and sometimes on the fruit and foliage. The male scale is much smaller and truncated at one end; it is rare.

These scales may encrust the trees so thickly that they die, especially young trees.

Not only Apple, but Pear, Currant, Hawthorn, and other plants are invaded by this insect, which is widely distributed over the world.

The female is a footless, fleshy body which lives under the scale with her long proboscis pushed into the plant; she lays her eggs under the scale, and these we find all the winter. In June they hatch into little active six-legged larvae which crawl over the trees and sooner or later fix upon some definite abode; then they look like small white specks, and by degrees the scaly covering is built up. The male has two wings.

Treatment

Winter spraying with caustic soda or Woburn Winter Wash, and spraying when the larvae are free, towards the end of June, with dilute paraffin emulsion.