2i6 GEOLOGICAL SURVEY OF NEW JERSEY. 



death, and I have seen examples where all external wounds 

 Avere healed o\er }'ears since, }'et whose history of prior infesta- 

 tion was plainl}- 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 the}- are suitable, and the sections containing the 



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



larvse 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 injur\- when e\-en a 

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

 oak brush in South Jer.sey, and each year some portions are 

 more or less scorched. The sea.son following, almost ever\- one 

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

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

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

 the}- are full-grown, then to cut the tA\'ig from the inside until it 



