4 INSECTS INJURIOUS TO FORESTS. 
their work, is reddish to dunnish yellow in color and has a claylike 
consistency. The mines eventually end in a broad chamber, the 
entrance to which is plugged up by the excelsior-like fibers of wood 
chiseled out by the strong mandibles of the larva. Here the resting 
stage (fig. 3), or pupa, is formed, and in this chamber the perfect adult 
spends considerable time before emerging. Often all stages from very 
young larvae only about one-fourth inch long to full-grown larvae over 
1 inch long, pupae, and 
adults in all stages to 
maturity are present in 
the same pole. Adults 
have been found flying 
from July to Septem- 
ber. As yet the sea- 
sonal history of this 
borer has not been com- 
pletely worked out. 
DISTRIBUTION. 
Fig. 2.— The chestnut telephone-pole borer: Female beetle, three tniS insect IS Very 
and one-half times natural size. Head and pronotum of male widely distributed 
beetle. (Original). • t> r\ j. ' 
ranging from Ontario, 
Canada, to Texas, eastward to the Atlantic coast, and westward to 
Arizona and southern California. It is common throughout the 
natural range of the chestnut — and in this connection it should be 
observed that most of the chestnut poles are purchased from local 
timber-land owners. 
CHARACTER OF THE INJURY. 
The injury to the poles consists in large mines in the wood near the 
line of contact of the pole with the ground, necessitating the frequent 
resetting or even the replacement of the damaged poles. These 
irregular galleries of the grub (Plate II, fig. 1) run both horizontally 
and longitudinally throughout the heartwood, and are sometimes 7 
inches long, but vary with the individuals, which show great differ- 
ences in size. The borers usually work in the outer layers of the 
wood at the base of the pole for a distance of from 2 to 3 feet below, 
and sometimes from 1 to 2 feet above the line of contact of the pole 
with the surface of the ground. The greatest damage is to that area 
just below and just above the surface of the ground (Plate I, fig. 3); 
here the conditions of air and moisture are most favorable. Often 
the entire butt up to a distance of from 4 to 6 feet and higher, 
according to the depth of setting, is mined. The numerous galleries, 
often very close together, completely honeycomb the wood in a zone 
