IN A REPORT in 1950, Lyle F. Watts, Chief of tree Forest Service, wrote: "Insects and diseases rank with fire as destroyers of forests. Ordinarily the damage caused by these pests is less conspicuous. But they are at work every year, and no forest area is entirely free from them. Their total effect probably exceeds that of fire."

The actual amount of loss insects cause to forests is hard to measure, but a few estimates have been made. An outbreak of the spruce budworm from 1910 to 1920 in balsam, fir, and spruce forests of Minnesota and Maine killed about 70 to 90 percent of the mature stand. The loss of timber was estimated at about 4.5 million dollars annually during that period. The Engelmann spruce beetle, in an outbreak in 1940 to 1946, destroyed about 20 percent of the Engelmann spruce timber in Colorado. The average yearly loss amounted to about 500 million board feet, valued at about i million dollars. The outbreak continued in 1951. An outbreak of the mountain pine beetle caused an estimated annual loss of 60 million board feet of lodgepole pine in Wyoming in 1946 and 1947. Some 15 million feet of ponderosa pine was destroyed by the Black Hills beetle in South Dakota in 1947.

An outbreak of the Douglas-fir tussock moth on more than 400,000 acres of forest near Moscow, Idaho, was brought under control in 1947 by DDT sprays applied from airplanes. The insect had defoliated the stands in 1946 and had killed the timber on about 16,000 acres. An estimated additional 1,518,856,000 board feet of timber, valued at $84,328,000, might have been killed had no steps been taken to prevent further defoliation.

Insects cause an average annual loss of at least 5 percent of the rice, corn, wheat, barley, oats, grain sorghums, and similar crops after they are harvested and while they are in storage on the farm, in elevators, or in warehouses. Much of this loss comes right on the farm and is more severe in the southern parts of the country where in the warmer temperatures the weevils, beetles, and moths breed and feed through most of the year. The actual amount of grain lost annually because of these pests has been estimated at 300 million bushels, worth more than 500 million dollars at 1951 prices. In the fall of 1947, entomologists estimated from samples of wheat taken from untreated bins in a Midwestern State that the farmers there and then were giving 380 billion insects free board and lodging in their grain bins.

Processed foods and packaged goods of various kinds get their share of insect damage, although such contamination is far less today than it was in our grandparents' time. One recalls the barrels of flour and cornmeal and the open boxes of dried prunes common in the local store not many years ago. How often, in buying these products, did one carry home meal infested with weevils and prunes covered with the excrement of the worms that infested them? Today if the housewife finds a sign of an insect in a package it goes back to the dealer. Our food and drug laws now insist that our food be free from insect contamination. Despite the advances, the meal and flour moths and the flour, grain, rice, and cigarette beetles still cause great damage to some processed foods and packaged goods. The annual loss in this country from those pests was estimated at 150 million dollars between 194o and 1944. The estimate includes the destruction caused by the pests in processing plants, warehouses, retail stores, and homes.

Every now and then a housekeeper has to discard a partly used package of cereal, meal, nuts, dried fruit, or other food which, forgotten on the pantry shelf, has become infested by moths, worms, or weevils the pantry pests. Suppose each family in the United States discarded only 5o cents worth of infested products a year: The loss would be about 20 million dollars.

The losses to clothing, rugs, furniture, and other furnishings by clothes moths, carpet beetles, and similar pests are estimated by entomologists to be from 200 million to 500 million dollars annually.

Such figures should give us pause. They are figures for fewer than 100 of the 600 or more injurious species of insects of primary importance that are known to occur in North America. They emphasize that everyone is affected in many ways by many insects, even though he might go for months without even seeing or noticing an insect or any signs of insect damage. Losses caused by all insects in the United States add up to a staggering amount, whether we regard it in terms of dollars, lost food and fiber, or time and materials used in combating them. That amount, in the opinion of entomologists, is at least 4 billion dollars for an average year-4 billion dollars.

G. J. HAEUSSLER is head of the division of truck crop and garden insect investigations in the Bureau of Entomology and Plant Quarantine. From 1944 to 1951 he was in charge of the division of insect survey and information. A graduate of the University of Massachusetts, he joined the Department in 1925. He was engaged for 16 years in investigations on the biological control of fruit insects.