Foreword

THIS PRACTICAL BOOK GIVES farmers and many other persons a great deal of information about the useful insects, as well as the harmful ones which are estimated to cost us four billion dollars a year.

It is a timely book. In helping us combat our insect enemies it helps us produce more food, feed, fiber, and wood, all of which we need more than ever before.

It is also a disturbing book—and that, to me, is one of its virtues. Although the science of entomology has made great progress in the past two decades, the problems caused by insects seem to be bigger than ever. We have more insect pests, although we have better insecticides to use against them and better ways to fight them. Effective though our quarantines are against foreign pests, some of them are slipping through and require vigorous attention. Many aspects need to be considered in the control of insects. We must stop the destruction of our crops and forests, but the insecticides we use must leave no dangerous residues on foods, destroy no beneficial wildlife, and do no damage to our soils.

We thought we had some of the problems solved when we got such good results from the new insecticides. DDT, for example, made medical history in 1943 and 1944 when an outbreak of typhus in Naples was controlled in a few weeks by its use. Entomologists hoped then that DDT could end all insect-borne diseases and even eradicate the house fly. In less than a decade, however, DDT was found to be a failure against the body louse in Korea, and the specter of typhus hung over that area. DDT and the insecticides substituted for it failed to control mosquitoes in some places. In 1952 the house fly was no longer controlled in many places by any of the residual-type insecticides in use, and it seemed likely that other pests ( those of agricultural, as well as medical, importance) in time would develop resistance.

The answer, like the challenge, is clear.

We dare not think of any knowledge—least of all knowledge of living things—as static, fixed, or finished. We need to push on to new horizons of thinking and investigation and, reaching them, see newer horizons. We need a longer view in research and an appreciation that it can have two goals : First, practical, everyday results that can be expressed in terms of definite methods, tools, and advice, and, second, fundamental, basic knowledge, on which the applied science rests.

A book like this and the long research that made it possible exemplify the first goal. But if we are to progress further in this vital work, we need to keep the second goal always before us, remembering that science and knowledge are ever-growing and ever-changing.

CHARLES F. BRANNAN, Secretary of Agriculture.