16 



begin to form through all stages of the seedling, the sapling, the young, 

 matured, old, dying, dead, and decaying tree. Not only does the tree, 

 during each stage in its life history, death, and decay, support some 

 kind or kinds of insects peculiar to each, but every part— the rootlets, 

 the larger branching roots, the main roots, the lower stem, the upper 

 stem, the large and small branches, the twigs, the buds, the young 

 leaves, the flower buds, the different parts of the flower, and the 

 embryo fruit— will have its special guests. Some kinds inhabit the 

 outer bark; others, the intermediate or inner bark, the cambium, the 

 outer or inner sapwood, the heartwood, or the pith. 



Not only during its life, but from the time it dies until it is entirely 

 decayed and converted into humus, a tree supports many and varied 

 forms of insect life. Some are its enemies, some its friends; others, 

 neither enemies nor friends, but guests and scavengers. Among 

 its enemies some have special designs upon its life in order that 

 its dying may furnish favorable conditions for the rapid increase 

 of the insect progeny, and consequent increased power in numbers 

 to attack and kill other trees. Some are enemies only to the extent 

 of causing injuries to the roots, bark, wood, branches, and foliage 

 which may be detrimental to its perfect development or its future 

 usefulness to man, but have little or no immediate effect upon its 

 vitality. Others are enemies only so far as they obtain their food 

 from some living part, yet do no permanent injury, such as certain 

 kinds of leaf-eating, sap-sucking, and gall-making insects, which aj'e 

 never or rarely common enough for special harm. There are many 

 other kinds which obtain their food directly from the dead parts of 

 the living tree, such as the outer bark, dead twigs and branches, dead 

 wood, etc., which can scarcelj' be considered as enemies of the living 

 tree. Among the friends of the living tree are the insects which feed 

 upon the injurious kinds, either as internal or external parasites, or 

 those which attack and devour their prey. Among the guests of the 

 injurious and beneficial inhabitants of the tree there are many kinds 

 which live in the burrows and feed upon the sap, borings, exci'ements, 

 dead insects, etc., while there are many other kinds which utilize 

 some part of the tree or the burrows of other insects as hiding or 

 hibernating places. 



THE INSECT FAUNA OP FOREST PRODUCTS. 



The natural products, such as nuts, medicinal roots, bark, and leaves, 

 tan bark, etc., each, under certain conditions of storage and age, fur- 

 nishes feeding and breeding places for many kinds of injurious, bene- 

 ficial, and neutral species. The manufactured or commercial wooden 

 products of all kinds, the crude round or square timbers, lumber, 

 staves, hoop poles, etc., are, under certain conditions, subject to attack 

 or serious injury from various kinds of insects while in the woods or 



