BORING BENEATH BARK OF TRUNK OR LIMB 241 
Where borers are present, cut them out with a knife, or probe the 
burrows with a soft copper wire. Knife wounds should be painted 
with white lead. 
The Shot Hole Borer (Eccoptogaster (Scolytus) rugulosus Ratz.) 
Plum, pear, apple, peach, and cherry are attacked by this tiny insect. 
The outward evidence of injury is seen in numerous round holes in 
the bark, each hole clean-cut, 
about one sixteenth of an inch 
in diameter, as if the trunk or 
limb had received a charge of 
bird shot. Asa rule only trees 
are attacked that have been 
weakened from some cause or 
other. 
If a piece of bark is removed 
where the holes are numerous, 
shallow galleries will be found 
beneath. These are of char- 
acteristic form. <A central 
gallery, one or two inches long, 
runs parallel with the axis of 
the trunk or limb, while from 
this many other galleries di- 
verge, quite small at the start Fig. 313.— Burrows of the Shot Hole 
Borer, disclosed by removal of bark. 
Original. 
but growing rapidly larger. 
A small, dark beetle makes 
the main gallery as its brood chamber, laying its eggs in pockets 
along each side. Grubs hatch from these, bore the diverging chan- 
nels as they grow, and finally come out as adult beetles, cutting 
round emergence holes through the bark. 
In northern sections there are two generations each year; in the 
South there are three. 
To control, remove and burn dead or dying trees in which the insect 
is breeding in large numbers. They will invariably spread from these 
R 
