INSECT DEPREDATIONS IN NORTH AMERICAN FORESTS. 65 



roundheaded and flatheaded wood-borers and timber beetles. Fre- 

 quently the insects continue the work in the unseasoned and even dry 

 lumber cut from logs which had been previously infested. They also 

 continue to work in mine props after they have been placed 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 hickory 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. (Hopkins, 1905a.) 



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 product is 

 often reduced, as a consequence, from 10 to 50 per cent or more. 

 (Hopkins, 1894^, 1905a.) 



Handle and wagon stock in the rough is especialh' 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. (Hopkins, 1905a.) 



Pulpwood, and cordwood 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. Ope example reported 

 from near Munising, Mich., represents a loss of $5,000 from injury to 

 spruce and fir pulpwood cut in the winter and kept in piles over 

 summer. 



MANUFACTURED UNSEASONED PRODUCTS. 



Ambrosia beetles and other wood 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, principally Pterocyclon mali Fitch, had entered 

 the wood to such an extent as to have reduced the value 50 per cent 

 or more within a few weeks. Oak, poplar, gum, and similar woods 

 often suffer severely from this class of injury, causing losses vary- 

 ing from 5 to 50 per cent. (Hopkins, 1905a.) 



