. Defects in timber caused by insects. Wood; Forest insects. 24 BULLETIN 1490, U. S. DEPARTMENT OF AGRICULTURE wood of all kinds of timber. They may either be stained black inside or be of the same color as the surrounding wood, and they may be free and open or filled with tightly-lodged boring dust, depending on the kind of insect making them. This boring dust does not fall out when the wood is jarred. Grub holes are made in the living tree, in the saw log, or in piled green lumber. In nearly all cases the injury is caused by the young borers, sawyers, or grubs, but occasionally also by adult
. Defects in timber caused by insects. Wood; Forest insects. 24 BULLETIN 1490, U. S. DEPARTMENT OF AGRICULTURE wood of all kinds of timber. They may either be stained black inside or be of the same color as the surrounding wood, and they may be free and open or filled with tightly-lodged boring dust, depending on the kind of insect making them. This boring dust does not fall out when the wood is jarred. Grub holes are made in the living tree, in the saw log, or in piled green lumber. In nearly all cases the injury is caused by the young borers, sawyers, or grubs, but occasionally also by adult termites or white ants (fig. 18), adult. Fig. 26. -Wonnhole defects in cedar, caused by the round-headed borer Cullidium antennatuin carpenter bees13 (fig. 19), or carpenter ants14 (fig. 20), or by the larvae of horntails 15 (fig. 21). Usually this type of injury is con- sidered as " wormholes, no living worms or decay," especially if the holes are stained black, and no further damage will result, except in rare cases. Grub holes constitute a standard defect and are also included under " equivalent ; They are often of considerable size 13 Xylocopa spp. 14 Gamponotus spp. 15 Tremex oolumba L„ or Sirex spp. ; they usually damage only dead wood or trees or logs that have been left in the woods too Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Snyder, Thomas Elliott, b. 1885. Washington, D. C. : U. S. Dept. of Agriculture
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Keywords: ., bookcentury1900, bookdecade1920, bookpublisherwa, booksubjectwood
