76 



while others are simply detrimental. The destructive injuries are those 

 caused by wood-boring insects, which render the wood worthless for 

 any practical use to man. The detrimental injuries are those which 

 produce defects in the wood and hasten the decay of the affected parts. 



CHARACTER AND EXTENT OF DAMAGE TO FORESTS BY INSECTS. 



Few x)ersons who have not given considerable thought to the subject 

 realize the serious character of insect depredations upon our forests 

 and forest products. This is evident from the ftict that the subject is 

 seldom discussed at the meetings of forestry associations and is rarely 

 referred to by writers upon forestry economy in this country. 



If we were to assert as our belief that the annual damage and loss 

 occasioned by insects to owners of forest and forest products in the 

 United States was greater than that caused to the same by fire, few 

 persons, if any, would believe that it could be possible. Yet, when we 

 come to consider the varied losses resulting from insect depredation, 

 both in a destructive and detrimental manner and in the general influ- 

 ence of their work upon the forest e(;onomy of the country, Ave believe 

 that such an assertion would not be far from correct. 



The pine and spruce killed by bark- beetles over vast areas in New 

 England and in the Southern States within the last few years has 

 caused an enormous loss of valuable timber 5 yet this is only a small 

 portion of the damage to timber by insects. That caused in oak by 

 the timber worms [LymexyJon sericeum and Evpsalu m'uiuta)^ the 

 Columbian timber beetle {GortJiylus columbianus), and the car])enter 

 moths of the family Cossid;e, to the chestnut by the chestnut timber 

 worm [Lymexylon sericeum), and to the tulip and other kinds of timber 

 by the Columbian timber beetle, all of w^hich attack living trees, will 

 equal that caused by many forest conflagrations. Then when we come 

 to consider the damage to the wood of dying, dead, and felled timber, 

 and the work of destruction only begun by fire and comidetcd bjMvood- 

 boring species, it appears to us that the damage caused by insects is at 

 least jequal to that caused by fire. 



There is also another feature of the question, and that is in reference 

 to the effect of the detrimental and destructive ravages of forest insects 

 upon the forestry economy of the country. Owing to the large amount 

 of timber destroyed and rendered defective by insects, it is necessary 

 for the manufacturers to cut over a larger area than would otherwise 

 be necessary in order to suj^ply the demand for the best grades of lum- 

 ber and other timber products. According to a statement by Hon. J. 

 Sterling Morton at the last meeting of the American Association of 

 Agricultural Colleges and Experiment Stations, the area cut over every 

 day m this country to supply the demand for forest products is 30,000 

 acres. From our observation in the lumber regions of West Virginia 

 it would indicate that at least 10 per cent less timber might be cut each 

 year for this ptirpose were it not for the detrimental ravages of insects 



