INSECT DEPREDATIONS IX NORTH AMERICAN FORESTS. 67 



Construction timbers and otlu-r woodwork in new and old build- 

 ings are often so seriously daniau^ed bv powder-po.^t beetles, white 

 ants, and other wood-borinc: insects that the ail'ecte<l material has 

 to be removed and rejilaced by new. or the entii'e structure torn down 

 and rebuilt. (Hopkins, r.XKV/.) 



Construction timbers in bi-idges and like structures, railroad ties, 

 telei)hone and teleijraph poles, mine props, fence posts, etc., are 

 sometimes seriously injuretl by wood-boring larva', termites, black 

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

 in efficiency from 10 to 100 per cent. 



INSECTS IN TIIKIH HKI.AIION To TIIK REUITTION OF FTTIRK SIPPMES OF 



TIMHKH. 



Insects not only reduce future supplies by killiiiir the mature 

 trees and destroying the wood of timber that is inaccessible for 

 utilization, but through injuries inflicted upon trees during the 

 floAvering. fruiting, germinating, seedling, and sapling periods of 

 early growth they prevent normal reproduction and development. 

 (Hopkins. 1904r/, lOOCc.) 



INTERRELATIONS OF IY)REST INSECTS AND FOREST FIRES. 



Investigations conducted by the writer and assistants in all sec- 

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

 quite conclusively that the average percentage of loss of merchant- 

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

 insects during a five or ten year ])eriod is infinitely greater than 

 most people realize. (Hopkins, lOOCV/, pp. 4-5. lOORA. p. 34r). 1900/>, 

 pp. T), 24: Forbes, 1009, pp. r>l-r>2.) 



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

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

 entire country killed ami reduced in value l)y insects would represent 

 an average loss of $02,500,000 annually." 



It has been estimated ( Iloi^kins, 1905A. p. 5: I'.tos^/. p. [{V2) that 

 the Black Hills beetle killed approximately 1.000.000.000 feet b. m. 

 of timber during a period of Icn years, which at i^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 

 barkbi'ctle in a single national forest.'' (See also j). 70.) 



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

 ing of the American .Vssociation of Economi c Entomologists, held afc 



<^LnHnrs from fnrrst firrx.—li lias been estinintefl that "on the average, since 

 ISTO. forest tires have yesirly cost .^."(O.ooii.niMi in liinber." (rieveland. T.. jr.. 

 V.M)!). |). ?,.) 



''It has Immmi estiniated that (he losses «vf liiiiher from forest tires on jili of 

 the National Forests of the Inlted States from llMi.". id llios, iiulnsive. avenme- 

 oiil.v .$ir).'.0«»2 ainmally. ( Clevelanil. T.. jr.. l!H>s. p. r>41.) 

 12877— P.nii. ~>S, pt ."i— 09 3 



