INSECT DEPREDATIONS IN NORTH AMERICAN f 67 



, 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. (Hopkins, 1905a.) 



Construction timbers in bridges and like structures, railroad ties, 

 telephone and telegraph poles, mine props, fence posts, etc., are 

 sometimes seriously injured by wood-boring larva-, termite.-, black- 

 ants, carpenter bees, and powder-posl beetles, and sometimes reduced 

 in efficiency from 10 to 100 per cent. 



[NSECTS IN THEIR RELATION To THE REDUCTION OF FUTURE BUPPLIES "I 



TIMBER. 



Insects not only reduce future supplies by killing the mature 

 trees and destroying the wood of timber that is inaccessible for 

 utilization, but through injuries inflicted upon tree> during the 

 flowering, fruiting, germinating, seedling, and sapling period- of 

 early growth they prevent normal reproduction and development. 

 (Hopkins. 1904^, 1906c.) 



INTERRELATIONS OF FOREST INSECTS AND FOREST FIRES. 



Investigations conducted by the writer and as>i>tant- in all sec- 

 tions of the country during the past ten years indicate to them 

 quite conclusively that the average percentage of los> of merchant- 

 able timber in the forests of the entire country to be charged to 

 insects during a five or ten year period is infinitely greater than 

 most people realize. (Hopkins, 1906a, pp. 4-5. 1908/;, p. 345. 19096. 

 pp. 5, 24: Forbes, 1909, pp. 51-52.) 



Losses from forest insects. — The writer estimates (p. 70) that for 

 a ten-year period the average amount of timber in the forests of the 

 entire country killed and reduced in value by insects would represent 

 an average loss of $62,500,000 annually. 



It has been estimated (Hopkins. 19056. p. 5: 1908a, p. 162) that 

 the Black Hills beetle killed approximately 1.000,000.000 feet b. m. 

 of timber during a period of ten years, which at $2.50 per thousand 

 would amount to an average of $250,000 annually. This is merely 

 one example of very destructive depredations by a single species of 

 barkbeetle in a single national forest.'' (See also p. 70.) 



Prof. Lawrence Brunei*, state entomologist of Nebraska, at a meet- 

 ing of the American Association of Economic Entomologists, held at 



a Losses from forest fires. — it has been estimated that "on the average, since 

 1S70, forest fires have yearly cost $50,000,000 in timber:' (Cleveland, T., jr.. 

 VM)\). p. 3.) 



b It lias boon estimated that the lossrs of timber front forest tiros on all of 

 the National Forests of the United states from L905 to L908, inclusive, average 

 only $165,062 annually. (Cleveland, T., jr.. 1908, p, 541.) 



