216 GEOLOGICAL SURVEY OF NEW JERSEY. 



death, and I have seen examples where all external wounds 

 were healed over years since, yet whose history of prior infesta- 

 tion was plainly to be read when the trunk was split, the old 

 burrows found and the gnarled and twisted tissue of the old 

 entrance laid bare. These defects are never repaired, and a 

 burrow once made in the heart-wood of oak is there for all time. 

 Trees of this kind should be selected for firewood or for such 

 purposes as they are suitable, and the sections containing the 



Figure 6. Goat moths : female above, male below, and larva : from Riley. 



larvae should be used not later than June ist, to prevent the 

 emergence of the moths. The cutting should be done, of course, 

 in winter. 



Scrub land is peculiarly subject to insect injury when even a 

 small fire has been through it. There are hundreds of acres of 

 oak brush in South Jersey, and each year some portions are 

 more or less scorched. The season following, almost every one 

 of the shoots or saplings will be infested by round-headed borers 

 of the genus Elaphidion^ commonly known as " oak-pruners." 

 Their normal habit is to bore into oak twigs or branches until 

 they are full-grown, then to cut the twig from the inside until it 



