arsenic in some form. Success depends upon the poisonous 

 quality of the insecticide and upon the time and manner of 

 spraying. The principal leaf-eating insects are: Tussock 

 moth, Gypsy moth, Brown tail moth, Fall webworm, Bag worm, 

 Elm leaf beetle. Sucking insects are usually destroyed by 

 contact poisons such as kerosene emulsion, whale oil soap and 

 lime sulphur wash which close up their breathing pores. 

 Important sucking insects are the Cottony maple, Woolly ma- 

 ple, San Jose, scurvy, and oyster shell scales, and plant lice. 

 Boring insects such as the leopard moth, maple borers and 

 bark borers, are more or less successfully combatted by run- 

 ning a wire into the burrows, cutting off infected branches 

 and twigs, injecting carbon bisulphide into the galleries. 

 Fungus diseases affect leaves, branches, bark, sapwood and 

 heart wood and root, but are less serious than injuries by in- 

 sects, except the chestnut blight for which no remedy is 

 known. Diseases of the leaves may usually be controlled by 

 proper spraying with a good fungicide, such as Bordeaux mix- 

 ture. Fungi affecting the wood usually gain lodgment in 

 wounds. They may be excluded by proper care, and when 

 present may be checked by tree surgery methods. To suc- 

 cessfully combat tree pests of any description requires special 

 methods adapted to each particular pest. Detailed informa- 

 tion should be obtained from city, state or national authori- 

 ties. The American Forestry Association will refer inquiries 

 on these subjects to the proper officials on request. 



Tree surgery consists in cutting out the diseased parts of 

 trees and filling the cavities with cement so that they are 

 water-proof. All decaying, discolored, water-soaked wood 

 should be removed, with gouge, chisel and mallet, until only 

 sound, uninfected wood is exposed. The bottom of the cavity 

 should be shaped so that if water were thrown in the cavity 

 it would promptly run out. The top and bottom of the cavity 

 should be V-shaped rather than square or rounded, as this aids 

 proper healing. The interior of the cavity should be sterilized 

 by thorough painting with coal-tar creosote, followed by a 

 heavy coating of coal tar. Fill the cavity with mortar made 

 of one part cement to three (or less) parts sharp sand, and 

 bring the filling to a smooth, water-tight finish, exactly even 



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