STATE PLANT BOARD Issued December 8. 1910. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY— CIRCULAR No. 128. L. O. HOWARD, Entomologist and Chief of Bureau. INSECT INJURIES TO FOREST PRODUCTS. A. D. HOPKINS, In Charge of Forest Insect Investigations. 64135° 10 WASHINGTON : GOVERNMENT PRINTING OFRCE : 1910 A ^3 BUREAU OF EXTOMOLOGY. L. O. Howard, Entomologist and Chief of Bureau. C. L. Marlatt, Assistant Entomologist and Acting Chief in Absence of Chief. R. S. Clifton, Executive Assistant. W. F. Tastet, Chief Clerk. F. H. Chittenden, in charge of truck crop and stored product insect investigations. A. D. Hopkins, in charge of forest insect investigations. W, D. Hunter, in charge of southern field crop insect investigations. F. M. Webster, in charge of cereal and forage insect investigations. A. L. QuAiNTANCE, in chavgc of deciduous fruit insect investigations. E. F. Phillips, in charge of hee culture. D, M. Rogers, in charge of preventing spread of moths, field work. RoLLA P. CuRRiE, in charge of editorial toork. Mabel Colcord, librarian. Forest Insect Investigations. A. D. Hopkins, in charge. H. E. Burke, J. L. Webb, Josef Brunner, S. A. Roiiwer, T. E. Snyder, W. D. Edmondston, agents and experts. Mary E. Faunce, preparator. William Middleton, Mary C. Johnson, student assistants. [Cir. 128] II Circular No. 128. Issued December 8, 1910. United States Department of Agriculture, BUREAU OF ENTOMOLOGY. L. O. HOWARD, Entomologist and Chief of Bureau. INSECT INJURIES TO FOREST PRODUCTS." By A. D. Hopkins, In Charge of Forest Insect Investigations. Damage is caused by various species of insects which are attracted by the varying conditions prevailing at different stages during the process of utilizing the forest resources, from the time the trees are felled until the logs are converted into the crude and finished product and until the latter reaches the final consumer, or even after it is placed in the finished article or structure. As a result, additional drains are made on the timber to meet the demand for the higher grades of lumber and for other supplies to replace those injured or * destroyed. From the writer's personal investigations of this subject in different sections of the country it is evident that the damage to forest products of various kinds from this cause is far more extensive than is generally recognized. This loss differs from that resulting from insect damage to standing timber in that it represents more directly a loss of money invested in material and labor. CRUDE PRODUCTS. Roundheaded borers, timber worms, and ambrosia beetles. — Round timber with the bark on, such as poles, posts, mine props, saw logs, etc., is subject to serious damage by the same class of insects as those mentioned under injury to the wood of dying and dead trees. The damage is especially severe when material is handled in such a man- ner as to offer favorable conditions for attack, as when the logs are left in the woods on skidways or in millyards for a month or more after they have been cut from the living trees. Under such condi- tions there is often a reduction in value of from 5 to 30 per cent or more, due to w^ormhole and pinhole defects caused by roundheaded and flatheaded wood-borers and timber beetles. Frequently the insects continue the work in the unseasoned and even dry lumber cut from logs which had been previously infested. They also con- o Revised extracts from Bulletin No. 58, Part V, Bureau of Entomology, U. S. Department of Agriculture, 1909. 64135° — Cir. 128—10 1 2 INSECT INJURIES TO FOREST PRODUCTS. tinue to work in mine props after they have been phiced in the mine, and in logs and other material used for the construction of cabins, rustic houses, etc.. and in round timbers generally. The products from saplings, such as hickor}^ hoop poles and like material, are often seriously injured or rendered worthless by round- headed and flatheaded borers and wood-boring beetles, sometimes resulting in a loss of from 50 to 100 per cent of the merchantable product. Stave and shingle bolts left in moist, shady places in the woods or in close piles during the summer months are often attacked by ambrosia beetles and timber beetles. The value of the pro^luct is often reduced, as a consequence, from 10 to 50 per cent or more. Handle and wagon stock in the rough is especially liable to injury by ambrosia beetles and roundheaded borers. Hickory and ash bolts from which the bark is not removed are almost certain to be greatly damaged if the logs and bolts cut from living trees during the winter and spring are held over for a few weeks after the middle of March or first of April. Pulp wood, and cord wood for fuel and other purposes, cut during the winter and spring and left in the woods for a few weeks or months or in close piles after the beginning of the warm weather, are sometimes riddled with wormholes or converted into sawdust borings, causing a loss of from 10 to 100 per cent. One example reported from near Munising, Mich., represents a loss of $5,000 from injury to spruce and fir pulp wood cut in the winter and kept in piles over summer. MANUFACTURED UNSEASONED PRODUCTS. Ambrosia beetles and other icood borers. — Freshly sawed hard- wood placed in close piles during warm, damp weather during the period from June to September is often seriously injured by am- brosia beetles. Heavy 2-inch to 3-inch stuff is also liable to attack by the same insects, even in loose piles. An example of this was found in some thousands of feet of mahogany lumber of the highest grade, which had been sawed from imported round logs and piled with lumber sticks between the tiers of plank. Native species of ambrosia beetles had entered the wood to such an extent as to have re- duced the value 50 per cent or more within a few weeks. Oak, poplar, gum, and similar woods often sutfer severely from this class of injury, causing losses varying from 5 to 50 per cent. Lumber and square timbers of both soft and hard woods with the bark left on the edges are frequently damaged by flatlieaded and roundheaded wood borers, which hatch from eggs deposited in the bark before or after the lumber is sawed. There are examples of ICIr. lliSj INSECT INJURIES TO FOREST PRODUCTS. 3 losses from this character of injury amounting to from 20 to 50 per cent or more. Telegraph and telephone poles, posts, mine props, etc., are fre- quently injured before they are set in the ground, especially if the bark remains on them during a few weeks after the middle of March. SEASONED PRODUCTS IN YARDS AND STOREHOUSES. Powder-post heetles. — Hardwood lumber of all kinds, rough handles, wagon stock, etc., made partially or entirely of sapwood, are often reduced in value from 10 to 90 per cent by a class of insects known as powder-post beetles. The sapwood of hickory, ash, and oak is most liable to attack. The reported losses from this source during the past five or six years indicate that there has been an average reduction in values of from 5 to 10 per cent or more. Old hemlock and oak tanbark is often so badly damaged by vari- ous insects which infest dead and dry bark that in some tanyards as much as 50 to 75 per cent of the bark that is over three years old is destroyed. In one tannery in West Virginia it is estimated that more than $30,000 worth of hemlock bark was thus destroyed. FINISHED PRODUCTS. The greatest loss of finished hardwood products, such as handle, wagon, carriage, and machinery stock, is caused by powder-post beetles. This is especially true of hickory and ash handles and like products in the large and small storehouses of the country, including the vast amount of material held in storage for the army and navy. When material of this kind is once attacked it is usually worthless for the purposes indicated, and therefore must be replaced with new material. In some cases losses have amounted to from 10 to 50 per cent, and it is estimated that the average losses have been as much as 10 per cent on nearly all sapwood material that has been in storage more than one year. UTILIZED PRODUCTS. Powder-post hettles^ white ants, and other wood-horing insects. — The finished woodwork in implements, machinery, wagons, furniture, and the inside finish in private and public buildings are often seri- ously damaged by powder-post beetles, thus requiring increased de- mands for new material. Construction timbers and other woodwork in new and old build- ings are often so seriously damaged by powder-post beetles, white ants, and other wood-boring insects that the affected material has to be removed and replaced by new, or the entire structure torn down and rebuilt. [Cir. 128] LIBRARY grATE pi-ant board 4 INSECT INJURIES TO FOREST PRODUCTS. Construction timbers in bridges and like structures, railroad ties, telephone and telegraph poles, mine props, fence posts, etc., are some- times seriously injured by wood-boring larvae, termites, black ants, carpenter bees, and powder-post beetles, and sometimes reduced in value from 10 to 100 per cent. PREVENTION OF INSECT INJURIES TO FOREST PRODUCTS. The problem of artificial control and prevention of insect injuries to forest products offers less difficulties perhaps than that relating to many other branches of the general subject of forest-insect control. In most cases the principle of prevention is the only one to be con- sidered, since the damage is done soon after the insects enter the wood, and therefore it can not be repaired by destroying the enemy. Crude Products. The proper degree of moisture found in the bark and wood of newly felled trees, saw logs, telegraph poles, posts, and like material, cut in the fall and winter and left on the ground or in close piles during a few weeks or months in the spring and summer or during the period when the particular species of injurious insects are flying, are some of the conditions most favorable to attack. The period of danger varies Avith the kind of timber and the time of the year it is felled. Those felled in late fall and winter will generally remain attractive to ambrosia beetles and adults of round and flat headed borers during March, April, and May. Those felled during the period between April and September may be attacked in a few days after they are felled, but the period of danger from a given species of insect may not extend over more than a few weeks. Thus certain kinds of trees felled during certain seasons are never attacked, while if they are felled at other times and seasons the conditions for attack may be most favorable when the insects are active, and then the wood will be thickly infested and ruined. The presence of bark is abso- lutely necessary for successful infestation by most of the wood-boring grubs, because the eggs and young stages must occupy the inner W(ler-i)()st injury, or (/>) treat with kerosene oil such infested and slightly injured articles as may be tested for required strength and found to be of sullicient value for retention, placing the same in <|uarantine for a sullicient time to determine whether the treatment is sncccssfid. ICir. 1-8] INSECT INJURIES TO FOREST PRODUCTS. 7 Damage b}^ powder-post insects to many kinds of articles can be pre- vented and at the same time the material otherwise benefited by treat- ing the sapwood with linseed oil or kerosene, either by immersing it in the oil or by applying the oil with a brush, the application to be made as soon as possible after the articles are finished from recently seasoned, uninjured stock. Past and Present Conditions of Powder-Post Injury. Up to 1906 there were a great many reports of extensive losses of valuable material from the ravages of powder-post beetles which were seriousl}- affecting all industries involved in the manufacture, sale, and utilization of the classes of hardwood products affected by them. In response to these reports and accompanying appeals to the Department of Agriculture for information on causes and remedies, the i^roblem was thoroughly investigated and specific advice and in- structions relating to practical methods of control and prevention have been widely disseminated, both through publications of the Department and special correspondence. Reports of present conditions from our principal correspondents, together with the less frequent requests for advice, indicate that the disseminated information has been extensively utilized and that it has been worth many millions of dollars toward eliminating the losses and reducing the drain on the limited supply of the kinds of timber required to replenish the damaged and destroyed material. The army and navy stores of handles, tent poles, wheelbarrows, oars, and many other hardwood articles have suffered severely from powder-post damage, involving an enormous loss, but the carrying out of the information already supplied has evidently contributed greatly toward the elimination of this source of loss to the Gov- ernment. Tan Park. Damage to hemlock and oak tan bark by the class of insects which in some cases has been so destructive to these products in the past can be easily prevented without cost, as follows: (1) Utilize the bark within three years from the time it is taken from the trees. (2) Prevent the accumulation in the yards and store sheds of old bark and waste material in which the insects can breed. These simple methods have been extensively adopted since their recommendation in correspondence and publications between about 1894 and 1904, and afford one of the most striking examples of the value of expert information on the peculiar habits of insects and of how millions of dollars can be saved without cost through a simple adjustment in methods of utilization. [Cir. 128] 8 INSECT INJURIES TO FOEEST PRODUCTS. Utilized Products. Damage and loss from insect injuries to timber and other ^YOodwork in structures of various kinds, to telephone and telegraph poles, posts, railroad ties, mine props, etc., can be prevented to a large extent through the adoption of the proper methods of management or of treating the material with preservatives before and after it is utilized. TIMBERS AND WOODWORK IN STRUCTURES. Injuries to timbers and woodwork in dwellings, outbuildings, bridges, etc., by powder-post insects can be prevented as follows: ( 1 ) Use nothing but heartwood for the concealed parts most liable to damage. (2) If it is necessary to use all or part sapwood material, attack can be prevented by treating the sap portions Avith kerosene, coal tar, creosote, or linseed oil. Facilities for future treatment can be pro- vided wherever the rough or finished Avoodwork is exposed, as in outbuildings, bridges, etc., if care is taken to expose the sapwood portions. (3) If the untreated timbers and woodwork in old buildings show evidence of attack, the affected portions should be given a liberal application of kerosene. Damage by white ants, or termites, can often be prevented in the following ways : (1) By the use of nothing but sound wood for underpinning and foundation timbers and the removal of decaying timbers from old structures. (2) By preventing moist conditions of the wood in any i)art of the structure and especially that in foundation timbers. (3) By the treatment of timbers necessarily exposed to moist con- ditions with creosote, zinc chlorid, corrosive sublimate, etc. (4) If the timbers become infested, further progress of insect dam- age can be prevented by removing the badly damaged parts and soak- ing the remainder with kerosene, fumigating with bisulphid of carbon, and by removing any adjacent decaying or other wood in which the insects have been breeding or may breed, such as logs, stumps, etc. !.()() cahins and imHtic work. — Damage by bark and wood boring insects to the unbarked logs and poles used in rustic cabins, summer houses, fences, etc., can be largely prevented by cutting the matei'ial in October and November and utilizing it at once, or by piling it off the ground or under cover in such n manner as to offer the best facil- ities for the rapid and thorough drying of the inner bark before the middle of March or the 1st of April following. If these necessary [(Mr. rJHJ INSECT INJURIES TO FOREST PRODUCTS. 9 precautions are not taken, and there is evidence that insects are at work in the bark and wood, the damage can be checked by injecting bisulphid of carbon through natural or artificial openings in the affected bark, and immediately stopping these and other openings with putty or a similar substance. Poles^ posts, piles, ties, mine props, and similar products. — Insect damage to poles, posts, and similar products can be prevented to a greater or less extent by the preservative treatments which have been tested and recommended by the Forest Service for the prevention of decay. These should be applied before the material is utilized for the purposes intended, or, if it be attacked after it has been utilized, further damage can be checked to a certain extent by the use of the same substances. It is often of prime importance to prevent injury from wood- boring insects, for the reason that such injuries contribute to more rapid decay. Therefore anything that will prevent insect injury, either before or after the utilization of such products, will contribute to the prevention of premature deterioration and decay. Approved : James Wilson, Secretary of Agriculture. Washington, D. C, October 7, 1910. [Cir. 128] O I