a 
INSECTS INJURIOUS TO DECIDUOUS SHADE 
TREES AND THEIR CONTROL. 
CONTENTS. 
Page Page. 
NEMO dUClOLV soe ee ee 3 Spraying outfits for small operations_ 20 
The principles of shade-tree insect Spraying outfits for large operations_ 22 
POTUGE Ole ee ne Sah ee PE ee 10 SPUAVINE AGCESSOTICs © === eee 23 
The stomach-poison sprays—-----~_- 11 Spray-dilution table for ready refer- 
fhe. contact) ‘spraysee- 2 ao 11 GNC See eet ees 2 Se 29 
Treatment of tree wounds____--__~_- 14 Leaf-chewing insects ~---___--~-~-- 31 
Blin) treelcavitiess—— =. 15 | Bark, wood, and twig boring insects_ 52 
Pruning as related to insect injury__ 15 Sap-sucking “insects -— == = 74 
Stimulation of growth by fertiliza- Gall-making insects and mites_____ 88 
GT, Ce nC SL ea eee SS Se 16 Deciduous shade-tree insects ar- 
Miscellaneous insect-killing imple- ranged according to the manner 
Mens! jr S Sees ae tee See 16 of attack and kind and part of 
LUBE ech as Wie Eee es ee eee 17 treesSuDJeCt. toy isa a eS 95 
INTRODUCTORY. 
WHY INSECT INJURY IS PREVALENT ON SHADE TREES. 
The original home of the trees we plant along our highways and 
byways is the forest. There, whatever disadvantages they are ex- 
posed to, they have acquired a certain degree of resistance to and 
immunity from insect and probably other normal enemies. Trans- 
planted to our streets, parks, or home grounds they are relieved of the 
keen competition and other adverse conditions of wild forest life but 
lose most of the natural advantages of their customary association— 
sun and shade, moisture and humus—and their proper growth is 
hampered besides, especially in our cities, by a variety of unfavorable 
conditions. Hard packed ground, frequently disturbed, often poi- 
soned with oils or gases or charged with electric current, and uncer- 
tain or erratic water supply handicap the roots, while constant strug- 
gle with thoughtless or reckless man and greedy beast, limited sun- 
shine, and other vicissitudes above ground render their struggle for 
existence uphill work indeed. Trees so hampered lose much of their 
native power of resistance and are thereby rendered inviting, easy 
prey to a variety of disintegrating agencies most prominent among 
which are insects. This is promptly reflected in their appearance, 
which is a prime consideration in the usefulness of shade trees. No 
kind of tree or any part of it is wholly immune from insect. pests. 
Indeed, some parts of trees harbor a large variety of them, and trees 
are known to be subject to more or less severe attack by hundreds of 
kinds of insects. In a world thus swarming with these creatures, 
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