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) rugulosusRa.tz.) 

 Pluni, 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. As a 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 hmb, while from 



this many other galleries di- 

 verge, quite small at the start 

 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 in\'ariably spread from these 



Fig. 313.— Burrows of the Shot Hole 

 Borer, disclosed by removal of bark. 

 Original. 



