DAMAGE TO CHESTNUT POLES BY INSECTS. 9 



before the material is utilized for the purposes intended, or, if it be attacked after 

 it has been utilized, further damage can be checked to a certain extent by the use of 

 the same substances. 



It is often of prime importance to prevent injury from wood-boring insects, for the 

 reason that such injuries contribute to more rapid decay. Therefore anything that 

 will prevent insect injury, either before or after the utilization of such products, will 

 contribute to the prevention of premature deterioration and decay. 



Through the courtesy of the American Telephone and Telegraph 

 Company and the Forest Service, about 40 chestnut poles set in a 

 test line near Dover, N. J., were inspected by the writer on July 15, 

 1910, in company with engineers of the telephone company and Mr. 

 H. F. "Weiss, Assistant Director, Forest Products Laboratory, Forest 

 Service, to determine the relative merits of various methods of pre- 

 venting damage by wood-boring insects to the bases of poles. In 

 this line, which is eight years old, variously treated poles alternated 

 with untreated poles in order that each chemical preservative and 

 method of treatment might be given an absolutely fair test under 

 the same conditions of site. The poles were 30 feet long, 7 inches 

 in diameter at the top, and 33 inches in circumference 6 feet from 

 the base. In this inspection the earth was removed (to a depth of 

 about 1 foot) from the base of the pole, and then the pole was chopped 

 into to determine the rate of decay. This method of inspection for 

 insect damage is not very satisfactory. The various methods experi- 

 mented with in this test line were brush treatments with a patented 

 carbolineum preservative and spirittine, charring the butt, setting 

 the pole in sand, and setting it in small broken stone. It was found 

 that, although these methods may temporarily check the inroads of 

 wood-boring insects, they wiU not keep the insects out of the poles. 

 The most serious damage to the poles in this line was by white ants. 

 Other insect damage was by a large black carpenter ant" and the 

 larvae of a round-headed borer. '' 



An inspection was made, between September 6 and 14, 1910, of 

 the bases of over 400 chestnut poles set in a similar test line near 

 Warren, Pa., and Falconer, N. Y. These poles were treated by the 

 creosote "open-tank" method of impregnation, and brush treatments 

 of creosote, wood creosote, creoUn, two different carbolineum pre- 

 servatives, and tar; they had been set in the ground for a period of 

 five years. All these treatments, except the brush treatments with 

 creolin and tar, were efficient in preventing the attacks of wood- 

 boring insects, at least for a five-year period, in this northern climate. 

 There was but little damage by insects to the poles in this test line. 

 The 'most common injury to the untreated poles was by the large 

 black carpenter ants which widen the longitudinal weathering checks, 

 and hence induce more rapid decay. The work of the chestnut tele- 



" Camponotiis pennsyhanicus Mayr. 

 6 Frionus sp. 



