Embattled Elms

For, lo, the winter is past, the rain is over and gone; the flowers appear on the earth; the time of the singing of birds is come . . .

. . . and the voice of the chain saw is heard in the land.

The Song of Solomon needed some new words last week as the power saws growled and stately old elm trees crashed to the pavement. They were all doomed by Dutch elm disease, though many of them could probably have been saved by careful, persistent programs of spraying with insecticides.

Even though the disease cannot be cured, sprays can kill the beetles that carry its deadly fungus from tree to tree. And if dead or dying trees are burned, the beetles have fewer places to breed. But still the plague spreads, even though many Middle Western cities, where elms are the most common and sometimes the only shade trees, have demonstrated that the two-part program works well. Chicago, which destroyed diseased trees and sprayed too, lost only 0.7% of its elms last year; Champaign-Urbana and Bloomington, where no systematic effort was made, lost 95% of their elms by 1960.

Loaded Worms. Early elm-saving sprays used DDT, and as Marine Biologist Rachel Carson recounted with telling effect in her bestseller, Silent Spring, the insecticide got into the soil and was absorbed by earthworms. When robins ate the worms, they died in large numbers. Quickly the notion spread through suburban folklore that any kind of spraying is deadly to all birds, even to squirrels, raccoons and other appealing mammals. Organized resistance to spraying began to appear. In Downers Grove, near Chicago, bird enthusiasts ran a loud campaign. They talked about "birdkill" and hinted that insecticides cause cancer in humans. They managed to stop spraying, and in the process they increased the loss of elms. The same battle is still being fought in many elm-shaded towns.

This spring the fight is hotter than ever. With Silent Spring as their gospel, birdmen are on the march all over the Middle West. But the tree people have rallied too. In spite of spraying, they point out, there seem to be plenty of birds around; and what are birds compared to elms? "In Kansas in August," said one elm lover, "you have to run from tree to tree to keep from getting sunburned to death."

Though both sides wallow in emotion, the facts seem to be that some kinds of spraying do reduce temporarily the local population of some kinds of birds. This is partly because spraying cuts the insect food supply, but when DDT is used in large quantities, it may also kill birds directly. When it gets into the soil, it may kill birds via contaminated earthworms for several years.

Bird-Sparing Spray. Responsible forestry experts argue that these ill effects can be minimized by spraying the elms in late fall or in early spring before the buds swell. At those times, few birds are around to be damaged, and when the bark beetles start flying in April from diseased to healthy elms, they are killed by the long-lasting poison. Another help would be substitution of methoxychlor for DDT. Methoxychlor is more expensive, but it kills bark beetles just as well, and it is only 10% as toxic as DDT to birds and other wildlife.

Spraying and burning are not likely to protect all elms, but with losses reduced to 1% or less, many of the tall old trees will survive, at least until fungus-resistant elms have had time to grow stately too. And the singing of the birds, if the sprayers are properly careful, will continue to be heard in the land.

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