Evening Republican, Volume 23, Number 73, Rensselaer, Jasper County, 24 March 1920 — Saving Forests From Insects [ARTICLE+ILLUSTRATION]

Saving Forests From Insects

- g a MPORTANT results have g*“A L been obtained in investigalajfj | tions of Insects affecting HrJ forest resources, accordins BCE PH to the annual report of the BRCj I chief of the bureau of entomology, United States depertinent of agriculture. The report says of western field work: “An especial investigation of the insect damage to crude spruce products for airplane stock io the states of Washington and Oregon showed that the greater part if not all of the damage could be prevented by proper methods of logging and production, with little or no additional cost. X- “Exhaustive studies of Insect investigation and control were continued in the Sequoia and Yosemite national parks. Much new information has been gained, and the methods of gathering and compiling field data have been standardised. “A special study was completed on the interrelation of forest fires and insects on an area of about 2,000 acres In southern Oregon. This area has been under observation since 1914, and the fire had burned over about 800 acres in 1918. The records show that previous to the fire the Insects had killed 485.000 board feet of timber. The fire killed 170,000 feet, and subsequently the slightly fire-injured as well as the uninjured trees in the burned area were killed by beetles, which were attracted from the surrounding areas. It was noticed that the infestation in the burned area Increased more than 1,000 per cent, but it was found that tKo Infestation In the surrounding arena decreased. It was also found that the broods of the beetles in the firescorched trees failed to develop to much beyond the original number that attacked 'the trees. So the fire did not contribute to an increase of the beetles in general area or to the starting or extension of an epidemic of beetles. This result is of extreme interest and hardly to be expected. “The most careful study ever made of the history of an epidemic infestation of tree-killing beetles was completed and a report submitted during the year. In the Rogue river area in about 48,000 acres near Ashland, Ore., the western pine beetle in 1914 caused the death of 346,000 board feet of pine timber In 1915, 1.615,000 board feet were killed; 1.383,000 f«et in 1916, and 608.000 in 1917. A count of the young and matured stages of the beetles that developed in an average foot of bark, and also of the number of exit holes through which the beetles emerged to attack other trees, showed that there was a notable decrease in numbers during the development of the broods each year in the Infested trees on account of the increase of natural enemies and other disturbing factors. This helps explain why these beetle epidemics rise and fall within a limited period of years, and It explains how the western forests of yellow pine are naturally protected from total destruction. These facts are especially significant in connection with the application of the percentage principle of control, as by aiding the natural forces which work against the abnormal Increase and epidemic shows the importance of prompt recognition and prompt treatment of a threatened outbreak In order to prevent the great Joss of timber which would occur before natural control became operative. “Another special study was made of i the number of all stages of the westjprn pine beetle In 330 square 'feet of tjnfesred bark selected from 67 trees, •which represented an average infestation within an area of approximately 36 square miles. It was shown that -there is a large percentage of mortality between the young and matured stages in the developing broods, but that normally an average of about 150 •beetles to the square foot of bark de■veioped to the adult, or reproductive stage, which would be 50.000 beetles ■ ■

to the average infested tree, or, say, 39,000 beetles to 1,000 board feet of timber. Since It requires an average of about 10 beetles to the square foot to attack and kill a vigorous, healthy tree, it will be seen that all the pine timber of the western forests would soon be destroyed were it not for natural and artificial control. “Experiments to determine the time of year to cut and the methods of handling mesquite for fuel, posts, etc., to avoid destruction by wood-boring insects, have been nearly completed, and the results show that serious loss In the Southwest can be prevented by cutting the trees In the late fall and early winter and piling the wood in loose piles until it is thoroughly dry. Damage to posts can be prevented by cutting them at any time and laying them on the ground where they will receive the full force of the sun, turning them occasionally so that the young stages of the borers will be killed by the heat. “Studies of damage to lead telephone cables In California by a woodboring beetle have been continued, and the results so far show that the beetle is able to penetrate alloyed substances that are considerably harder than lead.

The problem is still unsolved, and it will be difficult to find a practical means of controlling this pest, which Is able to put hundreds of telephones out of commission by boring holes In the cables, through which the water enters, rendering the wire connection useless until the place is found and repaired.” A feature of the national parks is their magnificent forests. These forests are always in danger of Insect foes. Eternal vigilance is the price of healthy forests. The work In general has hardly been begun. It will have to be put on a secure basis financially and made a regular part of national park administration. In a park like Rocky Mountain, which has at present an annual appropriation of but slo,ooo—a sum insufficient even for its protection and administration —insect control is, of course, practically neglected. The penalty will be paid later. In Yosemite a survey of the Yellow, Sugar, and Jeffry pine areas of the park made last spring developed the fart that Giese Species were exceptionally free from bark beetles, against which an active control campaign has been carried for several years. The condition tn the lodgepole areas is not so hopeful; in fact, it is serious. Large areas of this species have been entirely killed from the effects of the mountain-pine beetle during recent years, the worst and most recent being the almost complete destruction of the forests of the Tenaya basin. It is of interest to note that while

the actual killing of the trees Is due to the attacks of the bark beetle, the attacks of this insect are Invariably preceded by attacks on the foliage by an altogether different insect, the needle miner. The latter attacks the needles of the lodgepole, first discoloring the foliage and eventually causing complete defoliation. Curiously enough these attacks, although they may continue for several years, seldom are directly responsible for their death. They do, however, sap the vitality of the trees which, so weakened, fall prey to the bark beetle, which follows in due course. The lodgepole stand in and around the Tuolumne Meadows Is now threatened with destruction similar to that suffered by the stands in the Cathedral Creek and Tenaya Lake basins. During the season of 1918 the western pine beetle and mountain pine beetle killed aprpoximately 600,000 feet of merchantable yellow-pine and sugar-plne timber within the Marble Fork and Cactus Creek basins in Se quota national park, according to records from 183 trees marked and studied by the United States bureau of entomology. A fund left over from the project In the Middle Fork of the Kaweah river (unit Nd. TO, which had been completed) was expended in the treatment of this Infestation during the spring of 1918, but was insufficient to cover the entire area Involved. During the fiscal year 1919 the bureau of entomology carried on some work with its own resources in order to protect the area treated in 1918 and also to demonstrate and test a new method of applying the percentage of control. A method of destroying the broods of the western pine beetle without resorting to the use of fire is being developed, which, it is believed, will make possible the continuance of control work throughout the summer. Regarding eastern work the agricultural department says, in part: . “Continued experiments with chemical substances applied to finished and crude forest products show that very few of the many substances that have been tried are effective, and, with crude products, none of them Is so economical as simple and Inexpensive management in logging and manufacture which will render the conditions of the bark and the wood unfavorable to attack. “Continued studies of termite or white ant damage to the woodwork of buildings has led to the discovery that one of the most destructive species can not live if deprived of moisture tn ground or foundation timbers. “The recent appearance of the socalled seventeen-year locust, or periodical cicada, has given an opportunity for detailed study of certain points, and motion pictures have been made.**