BAFFLED BY AN INSECT.

Manawatu Standard, Volume LIII, Issue 313, 2 December 1933, Page 12

BAFFLED BY AN INSECT.

CREEPING PARALYSIS AMONG PINES. Creeping paralysis—caused by a minute troublesome insect has been attacking valuable British plantations of Douglas pine trees, and has defied all the efforts of forestry experts to arrest its development. During the last six years the insect —which is called chernes cooleyi—lias found its way to Northern Scotland, where it has fastened upon the trees and reduced them to an unsightly blackness. . Fortunately, tlie disease is only ot temporary duration, and alter a year or eighteen months the trees resume their interrupted growth. . Ten years ago the insect, which in appearance is a white variety of the green fly, was discovered in the South of England. Gradually it extended its operations to v&rious parts of England and Wales, causing temporary havoc among Douglas pines, to which its activities are limited, as it cannot live on other trees. . .' . “The outbreak is not serious in Scotland, being confined to Aberdeenshire and Rossshire,” an official of the Forestry Commission in Edinburgh told a reporter. “But it is no less annoying, as it retards the growth of trees until they have, so to speak, got the insect out of their system.” Actually there is, no cure for the malady. Young Douglas firs can be immunised, while still in the nursery, with a spray of soft soap and paraffin oil; but it would be too expensive to carry this out when the trees are fullgrown. Speaking for England a.nd Wales, an official of the Forestry Commission in London said that there was verv little trouble from the insect until ten years years ago. “Since then,” he said, “it has spread to other parts of the country and to Ireland. We are constantly experimentin”' and watching the effects of the successive onslaughts, but there is no known cure.” Douglas firs were first planted in the country about one hundred years ago.