The Moth That Ate Washington's Apple Boom

The ravages of the codlin moth, according to the reports of the United States government experts, exceed those of all other insects in the United States combined. It is estimated that one-fourth of all the apples raised in the country are rendered unsaleable by the insect, and the pecuniary loss is placed at $40,000,000 annually.

The greatest damage is done by the insects in the warm, sheltered valleys, just where the best apples can be grown. Along the Snake River some fruit men have dug up their orchards in despair, and some of the Walla Walla valley orchardists are fearful that they will have to do the same. W. S. Offner said at the recent fruit growers' convention in Portland that 75 per cent of his crop had been ruined by this baneful insect.

In the Yakima valley, where climatic conditions are similar to those in the Walla Walla, we have so successfully caught the insect that the ravages are much less. In my own case I have had in some years as much as 95 per cent of the fruit free from the effects of the insect, and rarely has the proportion of good fruit fallen below 80 per cent.

In fighting the insect I recommend the following series of treatments: First, spraying. Second, banding the trees. Third, clean culture. Fourth, picking off the young apples that are affected and burying them at least six inches deep. Fifth, protection to birds. Sixth, giving chickens the free run of the orchard.

In spraying use the following mixture: one-half pound of Paris green and from five to ten pounds of lime in every barrel of 45 gallons of water. The Paris green must be of the very best quality, and to sell any other kind is illegal in the state of Washington. The spraying should be done five times during the season—one each in May, June and July, and twice in August. As there are two or more broods of the codlin moth during the summer, it is important to kill the first brood as thoroughly as possible; this does very much to lessen the number of the later broods. The greatest damage is done late in the season because of the multiplication which has taken place owing to the several succeeding broods.

The spraying must be done thoroughly and a high pressure kept up in the pump. In the Yakima valley barrel sprays, with hand pumps, are commonly used, but the best spraying is done by a gasoline engine and a power sprayer, because we can keep up the pressure so much better by this means. Whatever spraying machine is used it must have a thorough agitator in order to keep the Paris green thoroughly stirred through the water. In my opinion for an orchard of 10 or more acres it will pay to have a power sprayer.

The bands are kept on during the entire season, the worms being taken out every twelve days until the middle of September, after which the bands are left on all winter, and in the early spring removed and the worms destroyed. Old burlap sacks may be used, being cut into strips eight inches wide and long enough to go around the tree and fastened with a shingle nail.

As we have to thin our apples, each person while doing so carries a little sack fastened over the shoulder with a strap, into which each wormy apple is placed. These are afterwards buried at least six inches deep. Thorough cultivation will destroy many of the worms or at least allow the birds to get them.