diately after the initial attacks of other species, as for 

 instance Hylurgops, Hylesinus, etc., in the base and roots; 

 Ips, Eccoptogaster, etc., in the trunks; also numerous flat- 

 heads (Buprestidae of the genera Buprestis, Melanophila, 

 Ghrysobothris, etc.) and roundhead "borers (Cerambycidae of 

 many genera) or Longhorn beetles, as they are sometimes call- 

 ed. In epidemic infestations some of the species become 

 primary to a small extent. Almost all the primary beetles 

 are secondary at times on individual trees. 



Insects attacking the branches are either smaller 

 flathead species or true bark-borers or --vood-borers p.nd, ex- 

 cept in seedlings and saplings, are seldom primary. In clo. 3 

 stands they are often beneficial, helping to prune the tree 

 of its lower branches. 



Many species of beetles also enter the wood, but 

 these Bpecies are seldom, if ever, primary. Many destroy 

 the sapwood and a few the heartwood. Depredations by these 

 insects are much lessened by peeling the bark. One group 

 called Ambrosia beetles or Pin-hole Borers carry the spores 

 of a fungus into the burrows which sometimes ce,uses the bluo 

 stain so common in recently killed trees and lumber. Their 

 presence can always be told by fine white sawchist in the 

 crevices of the bark. 



-39- 



