196 TREES AS GOOD CITIZENS 



snugly wrapped around the trunk in a way to fill all the 

 crevices of the bark. Over this there should be placed a 

 5 inch strip of building tar-paper, tightly drawn and 

 securely tacked at its overlapping ends. The sticky 

 substance is then applied to this paper. It should be 

 renewed when it becomes dry or covered with dust or 

 insects, as its stickiness is its one point of efficacy. 

 It should not come in contact with the tree, although 

 occasionally it is recommended to apply such material 

 directly to the trunk high enough to be above persons 

 passing. There is danger from a girdling effect due to the 

 hardening of the material (Hopkins, U. S. Dept. of Agr.) 

 and due to the penetration of possible injurious substances 

 in the material. A sticky fly-paper may be used, over 

 bands of cotton and with the edges securely bound with 

 string. 



Safeguards against insect attacks are as important in 

 their way as the application of remedies after the attacks 

 have taken hold. Much damage may be prevented by 

 advance precautions. Among the most important steps 

 of this character is the providing of good cultural condi- 

 tions and careful attention to all pruning, or accidental 

 injuries and cavities. 



Since trees which are strong and healthy are in best 

 position to resist insect attacks, it is important that weak- 

 ened trees should be stimulated by enrichment of the soil. 

 This may be accomplished by applying nitrate of soda, 

 stable manure, or other fertilizer containing nitrogen. 

 This stimulus, combined with pruning and frequent culti- 

 vation, will produce new vitality and prove helpful in 

 enabling a tree to combat its insect enemies with its own 

 forces. 



