6 



INSECT DAMAGE TO TELEPHONE AND TELEGRAPH POLES, 



only the butt, but also the basal area, is treated. If the pole is not 

 thoroughly brushed, the pole borer and other insects enter through the 

 untreated or imperfectly treated portions, especially through weath- 

 ering checks and knots. Where the base is left untreated, insects, 

 especially white ants or termites, enter the pole from below ground 

 and, avoiding the treated portions, come right up through the pole. 



Impregnating the poles with creosote by some standard process 

 (either by the open-tank or by a cylinder-pressure process) will keep 

 out wood-boring insects. In the open-tank method only the area most 

 subject to the attacks of wood-boring insects (i. e., the basal 8 feet) 

 is treated, while by the C3dinder-pressure processes the entire pole is 

 impregnated. 



Therefore, to effectually protect poles from the depredations of 

 wood-boring insects it is recommended that they be impregnated with 

 creosote by either the ''open-tank" process or by a cylinder-pressure 

 process. 



Approved : 



James Wilson, 



Secretary of Agriculture. 



Washington, D. C, January 2.'^, 1911. 



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