ENTOMOLOGY 325 



while if they are felled at other times and seasons the conditions for 

 attack may be most favorable when the insects are active, and then 

 the wood will be thickly infested and ruined. The presence of bark 

 is absolutely necessary for successful infestation by most of the wood- 

 boring gruDs, because the eggs and young stages must occupy the 

 inner and outer portions before the latter can enter the wood. Some 

 ambrosia beetles and timber worms will, however, attack barked logs, 

 especially those in close piles or otherwise shaded or protected from 

 rapid drying. A large percentage of the injury to this class of 

 products can be prevented, as follows : 



(1) Provide for as little delay as possible between the felling of 

 the tree and its manufacture into rough products. This is especially 

 necessary with trees felled from April to September in the region 

 north of the Gulf States and from March to November in the latter, 

 while the late fall and winter cuttings should all be worked up by 

 March or April. 



(2) Do not leave the round timbers in the woods or on the skid- 

 ways during the danger period, or, if this is unavoidable, take every 

 precaution to facilitate the rapid drying of the inner bark by keep- 

 ing the logs off the ground, in the sun, or in loose piles, or else, if 

 possible, the opposite extreme should be adopted and the logs kept in 

 water. 



(3) Remove the bark within a few days after the trees are 

 felled, from poles, posts, and other material which will not be in- 

 jured by checking or season cracks. 



(4) Take advantage of the proper months or seasons in which 

 to fell or girdle different kinds of trees to avoid danger. 



Damage to products cut from saplings and left with the bark on 

 can be prevented by transporting the material from the woods soon 

 after it is cut, so that it will not be left in piles or bundles in or near 

 the forest during the season of insect activity. Damage may also be 

 prevented by care not to leave the material stored in one place for 

 several months. 



Pinhole damage to stave and shingle bolts cut during a warm 

 season can be prevented by removing the bark from the timber as 

 soon as it is felled and by converting the bolts into the smallest prac- 

 ticable dimensions and piling them in such a manner as to facilitate 

 rapid drying. 



Damage to unseasoned handle and wagon stock in the rough 

 can be prevented by taking special precautions to provide against the 

 same favorable conditions for attack as mentioned in connection with 

 round timbers. This is especially necessary with hickory and ash 

 if cut during the winter and spring. 



Damage to pulpwood and cordwopd can be prevented to a great 

 extent by placing the sticks of wood in triangular or crib piles im- 

 mediately after they are cut from the trees, especially if the timber 

 is cut during the danger period or must be held for a few months 

 during the warm season. Peeling or splitting the wood, or both, be- 

 fore it is piled will also provide against damage from insects. 



