thus involving extensive waste and an increased drain on the forest 

 to supply clear lumber. This insect also attacks the oaks, and espe- 

 cially the red oak, the older trees of which are often as seriously 

 damaged as are the chestnut. 



Carpenter worms. The oaks, especially the white oak and the red 

 oak, are seriously damaged by carpenter worms of the genus Prion- 

 oxystus. The holes made by these insects through the heartwood of 

 the best part of the trunks are sometimes 1.5 inches in diameter one 

 way by 0.75 inch the other, thus causing serious damage to the wood. 

 These, with other large wood-boring beetle larvse, sometimes infest 

 the top part of the trunk and the larger branches of oak trees, where 

 their continued work results first in the dead and so-called " stag- 

 horn " top and subsequently in broken, decayed, and worthless trunks. 



Ambrosia beetles. One of the commonest defects in white oak, rock 

 oak, beech, whitewood or yellow poplar, elm, etc., is that known to the 

 lumber trade as " grease spots," " patch worm," and " black holes." 

 This defect is caused by one of the timber beetles or ambrosia beetles, 

 which makes successive attacks in the living healthy sapwood from 

 the time the trees are 20 or 30 years old until they reach the maximum 

 age. Thus the black-hole and stained-w r ood defect is scattered all 

 through the wood of the best part of the trunks of the trees. The 

 average reduction in value of otherwise best-grade lumber amounts, 

 in many localities, to from 25 to 75 per cent. The defect is commonly 

 found in oak and elm furniture and in interior hardwood finish in 

 dwellings and other buildings. 



The locust borer. The locust, as is well known, suffers to such an 

 extent from the ravages of the locust borer that in many localities the 

 trees are rendered worthless for commercial purposes or they are 

 reduced in value below the point of profitable growth as a forest tree ; 

 otherwise this would be one of the most profitable trees in the natural 

 forest or artificial plantation and would contribute greatly to an in- 

 creased timber supply. 



Turpentine beetles and turpentine borers. While the softwood 

 trees, or conifers, suffer far less than the hardwoods from the class 

 of enemies which cause defects in the living timber, there are a few 

 notable examples of serious damage. There is a common trouble 

 affecting the various species of pine throughout the country known 

 as basal wounds or basal fire wounds. It has been found that a large 

 percentage of this injury to the pine in the States north and west of 

 the Gulf States and in the Middle and South Atlantic States is 

 caused by the red turpentine beetle and in the Southern States by 

 the black turpentine beetle. These beetles attack the healthy living 

 bark at and toward the base of the trunks of medium to large trees 

 and kill areas varying in size from 1 to 10 square feet. These dead 



[Cir. 126] 



