11 



stumps and logs of felled ones, often for many years after the trees 

 are felled. One species sometimes attacks freshly sawed oak lumber, 

 new stave bolts, etc. They are among the most destructive enemies 

 of hard-wood forest trees, especially in reducing the value of the wood 

 of the best part of the trunks. 



THE CARPENTER WORMS. 



These are large pinkish caterpillars which are the larvae of stout- 

 bodied moths. They enter the bark and wood of living oak, locust, 

 poplar, and other trees from eggs deposited by the moths in the 

 crevices of uninjured bark, or in the edges of wounds. They burrow 

 deep into the solid wood, where they live for two or three years before 

 transforming to the adult. The wood is seriously injured by the very 

 large worm-hole defects, and while the life of the tree is but slightly, 

 if at all, affected by the earlier attacks, the continued operations of 

 this class of borers year after year finally results in the decay of the 

 heartwood, or a hol^jw trunk and a dead top. 



HORN-TAILS. 



This is a class of borers which are the larvae of the so-called wood 

 wasps. They may enter the exposed dead wood of wounds of living 

 trees, but more commonly attack the wood of dead standing conifers 

 and hard woods, in the sapwood of which they excavate irregular bur- 

 rows, which are packed with their borings. When the adults emerge 

 they leave the surface perforated with numerous round holes. Water 

 and fungi entering these holes cause a very rapid decay of the wood. 



POWDER-POST BEETLES. 



This is a class of insects representing two or three families of 

 beetles, the larvae of which infest and convert into fine power many 

 different kinds of dry and seasoned wood products, such as hickory 

 and ash handles, wagon spokes, lumber, etc., when wholly or in part 

 from the sapwood of trees. Oak and hemlock tan bark is sometimes 

 injured to a great extent, and the structural timbers of old houses, 

 barns, etc., are often seriously injured, while hoop poles and like 

 products are attacked by one set of these insects, the adults of which 

 burrow into the wood for the purpose of depositing their eggs. 



INSECTS INJURING LEAVES. 



THE TRUE CATERPILLARS. 



These are the larvae of butterflies and moths, and include a great 

 variety of forms which feed on the leaves of all kinds of forest trees. 

 Some attack the opening buds, others the very young leaves, while 



