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TREE PLANTER'S MANUAL. 



Bark-beetles are entirely dependent upon vegetable food, and spend 

 almost the whole period of their existence inside a plant. The only time 

 that they are found outside of their home lasts but a few hours, and these 

 moments they utilize for their love affairs, and to select a home for their 

 offspring. With few exceptions, all bark-beetles occur in the wood of 

 trees and shrubs, and but a very few species are found in parts of smaller 



Work of different kinds of Bark-beetles. In the figure at the right are seen the 

 primary and secondary tunnels, with the larvte in them. 



plants. None of them eat leaves and flowers. Most bark-beetles hibernate 

 in their perfect stage in the galleries made when larvae, and a few in the 

 pupal stage. Early in spring, or as soon as it is fairly warm, these beetles 

 awake from their torpid condition, and leaving the tree soon afterwards, 

 swarm outside their old home. As we have a large number of species of 

 these destructive insects, there is naturally a considerable difference in the 

 time of their swarming. Their flight is heavy and not very rapid. During 

 this time they have to search for proper places upon suitable trees in 

 which to deposit their eggs, which takes place soon after copulation. The 

 female beetle gnaws a hole into the chosen tree; after reaching a certain 

 depth, it usually turns at a right angle, and continuing makes a straight 



