DAMAGE TO CHESTNUT POLES BY INSECTS. 
3 to 4 inches in from the exterior of the poles; this so weakens the 
poles that they break off close to the surface of the ground. The 
basal 2 feet is usually sound. Even if the damage is not serious 
enough to cause the poles to break off under strain, they are likely to 
go down during any storm, and thus put the wire service out of com- 
mission; such damaged poles are a serious menace along the right of 
way of railroads. The beetle will attack poles that are perfectly 
sound, but evidently prefers to work where the wood shows signs of 
incipient decay; it will not work in wood that is "sobby" (wet rot), 
or in very "doty" (punky) wood. It has not yet been determined 
just how soon the borers usually enter the poles after they have been 
set in the ground. However, poles that had been standing only four 
or five years contained larva? and adults of this borer 
in the heartwood, and poles that had been set in the 
ground for only two years contained young larvae in the 
outer layers of the wood. 
Poles that appear sound on the exterior may have the 
entire basal interior riddled, and the work of the borers 
is not noticed until the poles break off. If merely iso- 
lated poles are injured, the poles that are broken off are 
held up by the wires and can be detected by the fact 
that they lean over, but if several adjacent poles are 
affected, especially where there is any unusual strain, 
that portion of the line is very likely to go down. The 
presence of the borers in injurious numbers can be de- 
termined only by removing the earth from about the 
base of the pole; the exit holes of the borer are found 
near the line of contact with the soil. Often large, 
coarse borings of wood fiber project from the exit holes. 
Sometimes old dead parent adults are found on the 
exterior of the poles underground. During August the 
young adults may be found in shallow depressions on the exterior of 
poles below the ground surface. 
Fig. 3. — The 
chestnut tele- 
phone-pole bor- 
e r : Pupa. 
Slightly more 
than twice 
natural size. 
(Original.) 
IMPORTANCE OF THE PROBLEM. 
The subject of the relation of insects to the rapid decay of chestnut 
poles has not been thoroughly investigated in the past, but now that 
the supply is becoming scarcer it is especially important to know 
what are the various primary causes of the deterioration of these 
poles, hitherto described under the vague term " decay." Although 
the chestnut telephone-pole borer has not hitherto been considered an 
insect of any economic importance, and has been described in ento- 
mological literature as only living under bark, principally of pine, or 
