26 



BULLETIN 1490, U. S. DEPARTMENT OF AGRICULTURE 



new growth of the tree, or they may have been enlarged by carpenter 

 ants. This type of injury can be recognized as follows: 



(1) In the sap wood and heart wood of hardwoods very large cir- 

 cular holes, one-half to 1 inch in diameter, are open and but slightly 

 stained and are usually lined with a silky yellowish-brown web 16 

 (Fig. 22.) * * 



(2) In sap wood or heartwood of hardwood trees the holes are 

 darkly stained and are open, containing little or no sawdust or f rass. 17 



(3) In the heart- 

 wood of butt logs of 

 gum and a few other 

 hardwoods, unstained 

 holes contain mined 

 granular and fibrous 

 frass 18 (fig. 23). 



(4) In the heart- 

 wood of butt logs of 

 softwoods, chiefly 

 pine, very irregular 

 holes are narrowly 

 oval, without stain, 

 but surrounded by 

 much pitchy " light- 

 wood," or " f atwood." 

 and are very tightly 

 packed with fine 

 granular frass 19 (fig. 



24) (;'). _ 



(5) Pinholes or 



w ormlioles in soft- 

 wood logs and lum- 

 ber in the Northern 

 States are caused by 

 a melandryid timber 

 worm. 20 These larvae 

 sapwood through scars or blazes and 

 The holes are filled with fine 



Fig. 28. — Powder-posted -white ash shipbuilding lumber 

 showing larval burrows and exit holes of adults of 

 Lyetus planicollis; board from a closely piled stack of 

 lumber throughout ■which larvae had burrowed 



gain entrance to the livin 



also attack recently felled :imber. 



sawdust. 



GRUB-HOLE INJURY TO GREEN SAW LOGS AND LUMBER; A PREVENTABLE LOSS 



All types of borer holes other than those mentioned above are made 

 after the trees have been felled, and are preventable by proper 

 methods of handling the logs. These borer holes occur in the sap- 



16 This injury is found principally in oak, chestnut, locust, and cherry and is caused by 

 the carpenter worm, Prionoxystus robiniae Peck. 



17 These holes are found principally in oaks and are caused by the round-headed borers 

 l Cerambycidae) Goes spp. and Romaleum sp. ; in hickory, they are caused by Goes sp. ; 

 in hickory in the South, small darkly stained holes are caused by a -wood-boring cater- 

 pillar, Cossula magnified Bailey; and' in hard maple they are caused by the maple-tree 

 borer, Glyeobius speciosus Say. 



1S This injury is caused by Parandra trunnea Fab. 



19 This injury is caused 'by Buprestis apricans Hbst. and occurs especially in fire- 

 scarred long-leaf pines and trees boxed for turpentine. This borer causes an excess of 

 pitchy wood near the injury. The injury often amounts to the reduction of 5 to 10 per 

 cent of the lumber to lower grades and the -wind-throw of much second growth on 

 turpentine operations. 



20 Serropalpus harbatus Schall. 



