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 will 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 a and the 
larvae of a round-headed borer. b 
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, creolin, 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- 
a Camponotus pennsylvanicus Mayr. 
b Prionus sp. 
