29 



tract from the usefulness of the wood. 



139. The pine bark beetle is an example of the insects 

 that actack the inner bark. It makes galleries in the inner 

 bark, which may girdle the tree and cause its death. In the 

 adult stage this insect is about three-eights of an inch long; 

 it is brown in color, sometimes nearly black. It can fly for 

 some distance, and spreads from place to place in this way. 

 Summer cutting in pine woods should be avoided as far as 

 practicable, because the odor of the resin attracts the bee- 

 tles to the neighborhood and often starts an outbreak that it 

 is hard to check. Sometimes a tree is struck by lightning, 

 the beetles are attracted to it, and they spread to surround- 

 ing trees. Its spread may be controlled by cutting and re- 

 moving the trees while the insects are in them. Their pres- 

 ence is shown by the fading of the foliage. To do any good 

 they must be removed before the beetles are gone, that is 

 before the foliage has turned brown. The infested trees 

 should be cut during December, January, and February. If 

 the trees are large enough for saw-logs, they should be saw- 

 ed at once, or be barked at once to expose the insects. If 

 they are used as firewood, they should be used before the 

 spring weather comes on, or some of the insects may escape. 

 The larger limbs, if not used as firewood, and the smaller 

 brush should be piled around the stumps and burned. 



140. The insects that prey on the foliage are also inju- 

 rious. If the foliage of pine trees is destroyed, they will 

 die. The broad-leaf trees are hardier; and they will stand 

 two or three defoliations before they succumb. But a les- 

 ening of the foliage, although it may not result in the death 

 of the tree, retards its growth, lowers its vitality, and les- 

 sens its resistance to future insect or fungous attacks. 



