. An annotated list of the important North American forest insects. Forest insects. 26 BULLETIN 1400, U. S. DEPAETMENT 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.^" (Fig. 22.) (2) In sapwood or heartwood of hardwood trees the holes are darkly stained and are open, containing little or no sawdust or f
. An annotated list of the important North American forest insects. Forest insects. 26 BULLETIN 1400, U. S. DEPAETMENT 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.^" (Fig. 22.) (2) In sapwood or heartwood of hardwood trees the holes are darkly stained and are open, containing little or no sawdust or f rass.^^ (3) In the heart- wood of butt logs of gum and a few other hardwoods, unstained holes contain mined granular and fibrous frass^s (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 f)ne granular frass ^^ (fig. 24) {??). (5) Pinholes or w o r m h o 1 e s in soft- Avood logs and lum- ber in the Northern States are caused by a melandryid timber '' These larvae gain entrance to the living sapwood through scars or blazes and also attack recently felled timber. The holes are filled with fine 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-. FiG. 28.—Powdpr-posted white ash shipbuilding lumber showing larval burrows and exit lioles of adults of Liictus planicoUis: board from a closely piled stack of lumber throughout which larvae had burrowed ^^ This injury is found principally in oak, chestnut, locust, and cherry and is caused by the carpenter worm, J'noiioj'ttstiis robiniae Peck. " These holes are found principally in oaks and are caused by the round-h
Size: 1488px × 1680px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorhopkinsadandrewdelmar, bookcentury1900, bookdecade1900
